SERVICE MANUAL

Nellcor Symphony ™
N-3000 Pulse Oximeter

To contact Nellcor Puritan Bennett’s representative: In the United States, call 1-800-NELLCOR or 510 463-4000;
outside the United States, call your local Nellcor Puritan Bennett representative.

Caution: Federal law (U.S.) restricts this device to sale by or on the order of a physician. 012 3

© 1996 Nellcor Puritan Bennett Incorporated. All rights reserved. 034129A-0296

Corporate Headquarters Regional/Local Offices

Nellcor Puritan Bennett Inc. Nellcor Puritan Bennett UK Ltd.

4280 Hacienda Drive 10, Talisman Business Centre
Pleasanton, California 94588 U.S.A. London Road
Tel. 510 463-4000 or Bicester
1-800-NELLCOR Oxfordshire OX6 0JX
Fax 510 463-4420 United Kingdom
Tel. +44.1869.322700
U.S. Service Repair Center
Nellcor Puritan Bennett Belgium NV/SA
Nellcor Puritan Bennett Inc. Interleuvenlaan 62/8, Zone 2
2391 Fenton Street B-3001 Heverlee
Chula Vista, California 91914 Belgium
U.S.A. Tel. +32.16.400467
Tel. 619 482-5000
Nellcor Puritan Bennett France Sarl
European Office 21 rue Albert Calmette
78353 Jouy-en-Josas Cedex
Nellcor Puritan Bennett Europe BV France
Hambakenwetering 1 Tel. +33.1.34.63.06.00
5231 DD ’s-Hertogenbosch
The Netherlands Nellcor Puritan Bennett Germany GmbH
Tel. +31.73.6485200 Black-&-Decker-Strasse 28
65510 Idstein
Asia/Pacific Office Germany
Tel. +49.6126.5930
Nellcor Puritan Bennett HK Ltd.
Room 1602 Evergo House Nellcor Puritan Bennett Italia Srl
38 Gloucester Road Via dei Tulipani, 3
Wanchai 20090 Pieve Emanuele (MI)
Hong Kong Italy
Tel. +852.2529.0363 Tel. +39.2.90786404

To obtain information about a warranty, if any, for this product, contact Nellcor
Puritan Bennett Technical Services or your local Nellcor Puritan Bennett
representative.

Nellcor Puritan Bennett, Durasensor , Nellcor Symphony , Oxisensor II, and the Nellcor
Puritan Bennett knob configuration are trademarks of Nellcor Puritan Bennett
Incorporated.

Covered by one or more of the following U.S. Patents and foreign equivalents:
4,621,643; 4,653,498; 4,700,708; 4,770,179; 4,869,254; 5,078,136; and 5,351,685.
TABLE OF CONTENTS
List of Figures
List of Tables

Section 1: Introduction ................................................................................ 1-1

1.1 Manual Overview........................................................................... 1-1
1.2 Warnings, Cautions, And Notes .................................................... 1-1
1.2.1 Warning............................................................................ 1-1
1.2.2 Caution ............................................................................. 1-1
1.2.3 Note.................................................................................. 1-1
1.3 N-3000 Pulse Oximeter Description .............................................. 1-1
1.4 Related Documents ....................................................................... 1-2
Section 2: Routine Maintenance ................................................................. 2-1
2.1 Cleaning ........................................................................................ 2-1
2.2 Periodic Safety and Functional Checks ......................................... 2-1
2.3 Batteries ........................................................................................ 2-1
Section 3: Performance Verification ........................................................... 3-1
3.1 Introduction.................................................................................... 3-1
3.2 Equipment Needed........................................................................ 3-1
3.3 Performance Tests ........................................................................ 3-1
3.3.1 Battery Operation Test ..................................................... 3-1
3.3.2 Battery Charge ................................................................. 3-2
3.3.3 Power-up Tests ................................................................ 3-3
3.3.3.1 Power-On Self-Test ......................................................... 3-3
3.3.3.2 Adult Power-On Defaults and Alarm Limit Ranges .......... 3-4
3.3.3.3 Neonate Power-On Defaults and Alarm Limit Ranges ..... 3-5
3.3.4 Operation with a Pulse Oximeter Tester .......................... 3-6
3.3.4.1 Alarms .............................................................................. 3-6
3.3.4.2 Alarm Silence ................................................................... 3-7
3.3.4.3 Alarm Volume Control ...................................................... 3-8
3.3.4.4 Pulse Tone Volume Control ............................................. 3-8
3.3.4.5 Dynamic Operating Range ............................................... 3-8
3.3.5 Normal Operation ............................................................. 3-10
3.3.5.1 LED Excitation Test ......................................................... 3-10
3.3.5.2 Operation with a Live Subject .......................................... 3-10
3.3.5.3 Serial Interface Test ......................................................... 3-11
3.4 Safety Tests .................................................................................. 3-12
3.4.1 Ground Integrity ............................................................... 3-13
3.4.2 Electrical Leakage ............................................................ 3-13
3.4.2.1 Chassis Source Current ................................................... 3-13
3.4.2.2 Patient Source Current .................................................... 3-14
3.4.2.3 Patient Sink Current ......................................................... 3-14
3.5 SpO2 Tests .................................................................................... 3-15
3.5.1 RCAL Circuit Test ............................................................ 3-15
3.5.2 LED Drive Tests ............................................................... 3-15
3.6 Piezo Speaker Test ....................................................................... 3-17
Section 4: Configuration Mode, Service Mode,
and Alarm Active Function .................................................................... 4-1
4.1 Introduction.................................................................................... 4-1
4.2 Configuration Mode ....................................................................... 4-1
4.2.1 Adult/Neonatal Mode Default ........................................... 4-2
4.2.2 Default SpO2 Upper Alarm Limit ...................................... 4-3
4.2.3 Default SpO2 Lower Alarm Limit ...................................... 4-3

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Table of Contents

4.2.4 Default Pulse Rate Upper Alarm Limit ............................. 4-3

4.2.5 Default Pulse Rate Lower Alarm Limit ............................. 4-4
4.2.6 Default Alarm Volume ...................................................... 4-4
4.2.7 Default Alarm Silence Duration ........................................ 4-4
4.2.8 Configuration Menu.......................................................... 4-5
4.2.8.1 Pulse Tone Volume.......................................................... 4-5
4.2.8.2 UIF Software Version Report ........................................... 4-6
4.2.8.3 SpO2 Software Version Report ........................................ 4-6
4.2.8.4 Set Serial Port Baud Rate ................................................ 4-6
4.2.8.5 Trend Type....................................................................... 4-6
4.2.8.6 Reset to Factory Defaults ................................................ 4-7
4.3 Service Mode................................................................................. 4-7
4.3.1 Menu Item 1: Software Version Report ............................ 4-10
4.3.2 Menu Item 2: Knob and Lamp Test .................................. 4-10
4.3.3 Menu Item 3: Button Test................................................. 4-10
4.3.4 Menu Item 4: Speaker Test .............................................. 4-11
4.3.5 Menu Item 5: Internal Configuration Code (ICC) Report .. 4-11
4.3.6 Menu Item 6: Total Operating Hours Report .................... 4-12
4.3.7 Menu Items 7-16: Error Log Record Report..................... 4-12
4.3.8 Menu Item 17: Instrument Identification (IID) Report ....... 4-13
4.3.9 Menu Item 18: Power Status............................................ 4-13
4.3.10 Menu Item 19: Persistent Time Sense Report ................. 4-14
4.3.11 Menu Item 20: Reset to Factory Defaults......................... 4-14
4.3.12 Menu Item 21: Initial Cluster Instrument Number Report . 4-14
4.3.13 Menu Item 22: Enable/Disable Latching Alarms .............. 4-15
4.3.14 Menu Item 23: Enable/Disable Alarm Silence Reminder . 4-15
4.3.15 Menu Item 25: Dump EEPROM Data .............................. 4-15
4.3.16 Menu Item 28: Enable/Disable Battery Charge Circuit..... 4-16
4.3.17 Menu Item 29: Instrument Compatibility Report ............... 4-16
4.3.18 Menu Item 30: SpO 2 RCAL Report .................................. 4-17
4.3.19 Menu Item 31: SpO 2 IR and Red Offset Report ............... 4-17
4.3.20 Menu Item 32: SpO 2 IR and Red Signals Report ............ 4-17
4.3.21 Menu Item 33: SpO 2 IR LED Drive Test........................... 4-18
4.3.22 Menu Item 34: SpO 2 Red LED Drive Test ....................... 4-18
4.3.23 Menu Item 35: SpO 2 DM-Gain Test ................................. 4-19
4.3.24 Menu Item 36: SpO 2 P-Gain Test .................................... 4-19
4.3.25 Menu Item 37: Set SpO2 Analog Test Mode .................... 4-20
4.3.26 Menu Item 38: SpO 2 A/D Cal Line Test ........................... 4-20
4.3.27 Menu Item 39: SpO 2 Enable Automatic Operation .......... 4-21
4.3.28 Menu Item 60: Set Serial Port Baud Rate ........................ 4-21
4.3.29 Menu Item 61: Serial Port Loop Back Test ...................... 4-22
4.3.30 Menu Item 62: Serial Port Transmit Test ......................... 4-22
4.4 Alarm Active Function.................................................................... 4-23
Section 5: Troubleshooting ......................................................................... 5-1
5.1 Introduction.................................................................................... 5-1
5.2 How to Use this Section ................................................................ 5-1
5.3 Who Should Perform Repairs........................................................ 5-1
5.4 Replacement Level Supported ...................................................... 5-1
5.5 Obtaining Replacement Parts ....................................................... 5-1
5.6 Troubleshooting Guide .................................................................. 5-2
5.6.1 Power ............................................................................... 5-3
5.6.2 Error Codes ...................................................................... 5-4
5.6.2.1 User-Correctable Error Codes ......................................... 5-4
5.6.2.2 Failure Error Codes.......................................................... 5-4
5.6.3 Buttons/Knob.................................................................... 5-7

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 Table of Contents

5.6.4 Display/Alarms ................................................................. 5-8

5.6.5 Operational Performance ................................................. 5-9
5.6.6 Stacked Operation ........................................................... 5-10
5.6.7 Serial Port ........................................................................ 5-11
Section 6: Disassembly Guide .................................................................... 6-1
6.1 Introduction.................................................................................... 6-1
6.2 Removing the Battery .................................................................... 6-1
6.3 Battery Replacement ................................................................ ..... 6-3
6.4 Fuse Replacement ........................................................................ 6-4
6.5 Monitor Disassembly ..................................................................... 6-4
6.5.1 Communications Board Switch Settings .......................... 6-5
6.6 Removing the Alarm Speaker ....................................................... 6-6
6.7 Removing the SpO2 PCB and SpO2 Controller PCB .................... 6-7
6.8 Removing the Communications PCB ............................................ 6-8
6.9 Removing the UIF PCB and Display PCB ................................ ..... 6-8
6.10 Control Knob Assembly Replacement........................................... 6-10
6.11 Lithium Battery Replacement ........................................................ 6-11
6.12 Reassembly................................................................................... 6-11
Section 7: Spare Parts ................................................................................. 7-1
7.1 Introduction.................................................................................... 7-1
Section 8: Packing for Shipment ................................................................ 8-1
8.1 General Instructions ................................................................ ...... 8-1
8.2 Repacking in Original Carton ........................................................ 8-1
8.3 Repacking in a Different Carton .................................................... 8-2
Section 9: Specifications ............................................................................. 9-1
9.1 General.......................................................................................... 9-1
9.2 Electrical ........................................................................................ 9-1
9.3 Physical Characteristics ................................................................ 9-2
9.4 Environmental ............................................................................... 9-2
9.5 Alarms ........................................................................................... 9-2
9.6 Factory Default Settings ................................................................ 9-2
9.7 Performance .................................................................................. 9-3
Appendix ....................................................................................................... A-1
A1 Integrity Tests ................................................................................ A-1
A2 Error Types.................................................................................... A-2
A3 User Correctable Error Codes ....................................................... A-3
A4 Failure Error Codes ....................................................................... A-3
A5 Internally Corrected Error Codes ................................................... A-4
Technical Supplement ................................................................................. S-1
S1 Introduction.................................................................................... S-1
S2 Oximetry Overview ........................................................................ S-1
S2.1 Automatic Calibration ....................................................... S-1
S2.2 Functional Versus Fractional Saturation .......................... S-2
S2.3 Measured Versus Calculated Saturation ......................... S-2
S3 Stackbus Interconnect ................................................................... S-2
S4 Circuit Analysis .............................................................................. S-3
S4.1 Functional Overview ........................................................ S-3
S4.2 Circuit Description ............................................................ S-4
S4.2.1 SpO2 Module .................................................................... S-4
S4.2.2 UIF Module ...................................................................... S-7
S4.2.3 SpO2 Controller ............................................................... S-15
S4.2.4 Communications Sub Module ......................................... S-17
S4.2.5 Display Board.................................................................. S-19
S5 Schematic Diagrams .................................................................... S-20

v
Table of Contents

LIST OF FIGURES

1-1 N-3000 Front Panel (North American) ............................................... 1-2

3-1 Self-Test Display ............................................................................... 3-3
3-2 Serial Port Interface ........................................................................... 3-11
3-3 N-3000 to External PC Connections .................................................. 3-12
3-4 Battery Cover Removal................................................................ ...... 3-17
3-5 Speaker Test...................................................................................... 3-18
4-1 Serial Port Pin Locations.................................................................... 4-23
6-1 Battery Replacement ......................................................................... 6-2
6-2 Removing the Battery ........................................................................ 6-3
6-3 N-3000 Fuses .................................................................................... 6-4
6-4 N-3000 Corner Screws ...................................................................... 6-4
6-5 Opening the N-3000 Monitor ............................................................. 6-5
6-6 Handle, Left Side Panel, and Speaker Disassembly ......................... 6-6
6-7 Rear Panel and SpO2 Module Disassembly...................................... 6-7
6-8 Communications PCB Removal ........................................................ 6-8
6-9 Display PCB and UIF Board Disassembly ........................................... 6-9
6-10 Knob Encoder Disassembly............................................................... 6-10
6-11 Knob Disassembly ............................................................................. 6-10
7-1 N-3000 Expanded View ..................................................................... 7-2
8-1 Repacking the N-3000 ....................................................................... 8-1
S2-1 Oxyhemoglobin Dissociation Curve ................................................... S-2
S4-1 N-3000 Functional Block Diagram ..................................................... S-4
S4-2 Timing Diagram ................................................................................. S-5
S4-3 Internal/External Stackbus Connections............................................ S-11
S4-4 Communications Submodule Block Diagram .................................... S-17
S4-5 Display Board Block Diagram ............................................................ S-19

LIST OF TABLES

3-1 Serial Port Voltages............................................................................ 3-12

4-1 Configuration Mode Menu .................................................................. 4-2
4-2 Configuration Menu ............................................................................ 4-5
4-3 Service Mode Steady State - Main Menu ........................................... 4-9
5-1 Problem Categories............................................................................ 5-2
5-2 Power Problems ................................................................................. 5-3
5-3 N-3000 Failure Error Codes ............................................................... 5-5
5-4 Buttons/Knob Problems...................................................................... 5-7
5-5 Display/Alarms Problems ................................................................... 5-8
5-6 Operational Performance Problems ................................................... 5-9
5-7 Stack Problems .................................................................................. 5-10
5-8 Serial Port Problems .......................................................................... 5-11
A-1 Error Types......................................................................................... A-2
A-2 N-3000 User Correctable Error Codes ............................................... A-3
A-3 N-3000 Failure Error Codes ............................................................... A-3
A-4 N-3000 Internally Corrected Error Codes ........................................... A-4
S4-1 J13 Inter Stack Connector ................................................................. S-8
S4-2 J8 Connector ..................................................................................... S-13
S4-3 J12, J22 Inter Module Connector ...................................................... S-14
S4-4 J5 Display Connector ........................................................................ S-14
S4-5 J2 Speaker Connector....................................................................... S-15
S4-6 J3 Knob Connector ............................................................................ S-15

vi
SECTION 1: INTRODUCTION
1.1 Manual Overview
1.2 Warnings, Cautions, and Notes
1.3 N-3000 Pulse Oximeter Description
1.4 Related Documents

1.1 MANUAL OVERVIEW

This manual contains information for servicing the Nellcor Symphony

model N-3000 pulse oximeter. Only qualified service personnel should service
this product. Before servicing the N-3000, read the operator’s manual
carefully for a thorough understanding of operation.

1.2 WARNINGS, CAUTIONS, AND NOTES

This manual uses three terms that are important for proper operation of the
monitor: Warning, Caution, and Note.

1.2.1 Warning

A warning precedes an action that may result in injury or death to the

patient or user. Warnings are boxed and highlighted in boldface type.

1.2.2 Caution

A caution precedes an action that may result in damage to, or malfunction of,
the monitor. Cautions are highlighted in boldface type.

1.2.3 Note

A note gives information that requires special attention.

1.3 N-3000 PULSE OXIMETER DESCRIPTION

The Nellcor Symphony N-3000 pulse oximeter is intended for continuous

noninvasive monitoring of functional oxygen saturation and pulse rate for
adult, pediatric, and neonatal patients in a hospital environment. It may be
used during hospital transport and in protected mobile environments such as
ambulances and helicopters when powered by its internal battery and
protected from excessive moisture, such as direct exposure to rain.

The N -3000 can operate as a standalone monitor or it can be connected to

(stacked with) the N-3100 blood pressure monitor.

The physical and operational characteristics of the monitor are described in

the operator’s manual and Section 9, Specifications , of this manual.

Figure 1-1 depicts the North American front panel of the N-3000 and the
names of its displays and controls.

1-1
Section 1: Introduction

1 2 3 4 5 6 7 8 9

Symphony N-3000

SpO2% PULSE RATE / min

LIMITS

NEONATAL
RF LOCK
LINKED
PRINT
MOTION PULSE SEARCH LEADS OFF

20 19 18 17 16 15 14 13 12 11 10

Figure 1-1: N-3000 Front Panel (North American)

1. SpO2 % display 11. PRINT button

2. PULSE AMPLITUDE indicator 12. BATTERY IN USE/BATTERY LOW indicator
3. ECG HEART RATE indicator * 13. BATTERY CHARGING indicator
4. PULSE RATE display 14. LINKED indicator*
5. AUXILIARY display 15. RF LOCKED indicator*
6. NEONATAL MODE indicator 16. LOWER ALARM LIMIT button
7. AUDIBLE ALARM OFF indicator 17. UPPER ALARM LIMIT button
8. ON/STANDBY button 18. LEADS OFF indicator*
9. POWER ON indicator 19. PULSE SEARCH indicator
10. STACKED indicator 20. PATIENT MOTION indicator
* Not used on this model

1.4 RELATED DOCUMENTS

To perform test and troubleshooting procedures and to understand the

principles of operation and circuit analysis sections of this manual, you must
know how to operate the monitor. Refer to the N-3000 operator’s manual. To
understand the various Nellcor Puritan Bennett sensors that work with the
monitor, refer to the individual sensor directions for use.

1-2
SECTION 2: ROUTINE MAINTENANCE
2.1 Cleaning
2.2 Periodic Safety and Functional Checks
2.3 Batteries

2.1 CLEANING

Caution: Do not immerse the N-3000 or its accessories in liquid or use

caustic or abrasive cleaners. Do not spray or pour any liquid on the
monitor or its accessories.

To clean the N-3000, dampen a cloth with a commercial, nonabrasive cleaner

and wipe the instrument exterior surfaces lightly. Do not allow any liquids to
come in contact with the power connector, fuse holder, or switches. Do not
allow any liquids to penetrate connectors or openings in the instrument cover.
Wipe sensor extension cables with a damp cloth. For sensors, follow
individual directions for use.

2.2 PERIODIC SAFETY AND FUNCTIONAL CHECKS

The following safety checks should be performed by a qualified service

technician after any repair or opening of the case, upon return of the
instrument from any use outside your institution’s control, or every 2 years.

1. Inspect the exterior of the N-3000 and verify that there is no evidence of
damage. Refer to Section 5, Troubleshooting for repair. If the N-3000
cannot be repaired, contact Nellcor Puritan Bennett’s Technical Services
Department or your local Nellcor Puritan Bennett representative.

2. Inspect safety labels for legibility. If labels are not legible, contact
Nellcor Puritan Bennett’s Technical Services Department or your local
Nellcor Puritan Bennett representative.

3. Verify that the monitor performs properly as described in paragraph 3.3.

4. Perform the electrical safety tests detailed in paragraph 3.4. If the unit
fails these electrical safety tests, do not attempt to repair, contact Nellcor
Puritan Bennett’s Technical Services Department or your local Nellcor
Puritan Bennett representative.

5. Inspect fuse(s) for proper rating (F1: 1.0 Amp, 250 Volt, Slo-Blow and F2:
2.5 Amp, 250 Volt, Slo-Blow). If necessary, replace as described in
paragraph 6.4.

2.3 BATTERIES

Nellcor Puritan Bennett recommends replacing instrument batteries at least

every 2 years. To replace the batteries, refer to Section 6, Disassembly Guide.

If the N-3000 has been stored for more than 30 days, charge the battery as
described in paragraph 3.3.2. A fully discharged battery requires a 14 hour
charge for a full charge. A 6-hour charge is required for 1 hour of operating
time.

2-1
SECTION 3: PERFORMANCE VERIFICATION
3.1 Introduction
3.2 Equipment Needed
3.3 Performance Tests
3.4 Safety Tests
3.5 SpO2 Tests
3.6 Piezo Speaker Test

3.1 INTRODUCTION

This section discusses the tests used to verify performance following

troubleshooting and repairs. All tests are accomplished through the control
panel.

3.2 EQUIPMENT NEEDED

Equipment Description
AC Power Adapter Nellcor Puritan Bennett model
SPS-N or SPS-N1
Safety Analyzer Must meet current AAMI
specifications
Sensor Cable SCP-10
Digital Multimeter (DMM) Fluke Model 87 or equivalent
Durasensor ® Oxygen Transducer DS-100A
Serial Interface Cable EIA-232 cable (optional)
Connector Adapter 6-pin, miniature
Oxisensor ® II Oxygen Transducer D-25
Pulse Oximeter Tester SRC-2
3.3 PERFORMANCE TESTS

Note: The battery operation and battery charge tests should be performed
before monitor repairs whenever the battery is suspected of being a
source of the problems. All other tests should be performed following
monitor repairs. Before performing the battery operation test, ensure
that the battery is fully charged (Paragraph 3.3.2).

3.3.1 Battery Operation Test

The monitor is specified to operate on battery power a minimum of 4 hours.

(This time may decrease if the N-3000 is operating in the stacked
configuration.)

1. Connect the Nellcor Puritan Bennett SRC-2 pulse oximeter tester to the
monitor.

2. Ensure that the monitor is not connected to AC power.

3-1
Section 3: Performance Verification

3. With the N-3000 turned off, press the ON/STANDBY button and verify
that the BATTERY IN USE/BATTERY LOW indicator lights after the
power-on self-test is completed.

4. The monitor must operate for at least 4 hours.

5. The BATTERY IN USE/BATTERY LOW indicator will start to flash

about 15 minutes before the battery fully discharges.

6. Allow the monitor to operate until it automatically powers down due to

the low battery.

7. If the monitor passes this test, immediately recharge the battery

(Paragraph 3.3.2, steps 1 - 3).

3.3.2 Battery Charge

Perform this procedure to fully charge the battery or after the Battery
Operation Test (Paragraph 3.3.1). This procedure should be performed, if
possible, before repair work is attempted.

1. Connect the monitor to an AC power source using the external power

supply.

2. Verify that the monitor is off and that the BATTERY CHARGING
indicator is lit.

3. Charge the battery for at least 14 hours.

Note: The BATTERY CHARGING indicator is timed to go out when

the N-3000 has been turned off and connected to AC power for
14 hours. Likewise, if the monitor is turned on and connected to
AC power for 14 hours (with no power interruptions), the
indicator goes out.

An illuminated BATTERY CHARGING indicator is not

necessarily an indication that the battery contains less than a
full charge. It is merely used as a timer to indicate that the
battery has been continuously charging for less than 14 hours.

4. If unsure whether the battery is functioning properly, perform the

procedure in Paragraph 3.3.1 “Battery Operation Test”.

5. Repeat this procedure (3.3.2 “Battery Charge”) through step 3 before

returning the monitor to service.

3-2
 Section 3: Performance Verification

3.3.3 Power-up Tests

The power-up tests (3.3.3.1 through 3.3.3.3) verify the following monitor
functions:

• Power-On Self-Test
• Adult Power-On Defaults and Alarm Limit Ranges
• Neonate Power-On Defaults and Alarm Limit Ranges

3.3.3.1 Power-On Self-Test

1. Connect the monitor to an AC power source using the external power

supply and verify that the BATTERY CHARGING indicator is lit.

2. Do not connect any sensor cables to the monitor.

3. Observe the monitor front panel. With the monitor off, press the
ON/STANDBY button. To successfully complete the self-test, the monitor
must perform the following sequence.

a. The monitor emits three consecutively higher pitched beeps.

b. All indicators light for a few seconds as illustrated in Figure 3-1.

Verify that the SpO2 % (left-most display), PULSE RATE (middle),
and AUXILIARY (right) displays all indicate “8.8.8.”.

Symphony N-3000

SpO2% PULSE RATE / min

LIMITS

NEONATAL
RF LOCK
LINKED
PRINT
MOTION PULSE SEARCH LEADS OFF

Figure 3-1: Self-Test Display

c. All displays turn off momentarily.

d. Digital displays individually light in a scanning, or firefly, test

pattern while the test is taking place.

e. A single, 1-second beep is produced and all displays again illuminate

momentarily, indicating that the automatic power-on self-test is
complete. The beep may sound before all the displays have lit in the
scanning sequence.

f. The POWER ON indicator and the BATTERY CHARGING indicator

are illuminated. The SpO 2%, PULSE RATE, and AUXILIARY
displays are blank. (If an SpO2 sensor cable and sensor were
connected, “0” would be displayed in both the SpO2 % and PULSE
RATE displays.) This is referred to as the normal mode steady state.

g. Press and hold the NEW PATIENT/NEONATAL button (located on

the rear panel) for 3 seconds until you hear three beeps, indicating
that stored patient data is cleared.

3-3
Section 3: Performance Verification

3.3.3.2 Adult Power-On Defaults and Alarm Limit Ranges

Note: This paragraph and paragraph 3.3.3.3 are written using Nellcor
Puritan Bennett factory-set defaults. If your institution has
preconfigured custom defaults, those values will be displayed.
Factory defaults can be reset using the service mode procedure
described in paragraph 4.3.11, Menu Item 20, Reset to Factory
Defaults, or the configuration mode procedure described in
paragraph 4.2.8.6.

When observing or changing default limits, a 3-second timeout is in

effect, that is, if no action is taken within 3 seconds, the monitor
automatically returns to the normal mode steady state.

1. Ensure that the monitor is on. Press and release the UPPER ALARM
LIMIT button. Verify that the monitor emits a single beep and the
SpO 2% display indicates an alarm limit of “100” for 3 seconds. Verify
that the other displays indicate a single bar at the top of each window
while the “100” is displayed.
SpO2 % PULSE RATE/ min

At the end of the 3 seconds, the displays indicate dashes (normal mode
steady state).

2. Press and release the UPPER ALARM LIMIT button. Begin rotating the
control knob counterclockwise (CCW) within 3 seconds. Verify that the
SpO 2% display reduces to a minimum of “85.”.

Note: A decimal point in the display indicates that the alarm limits
have changed.

3. Press and release the LOWER ALARM LIMIT button. Verify that the
monitor emits a single beep and the SpO 2% display indicates an alarm
limit of “85” for 3 seconds. Verify that the other displays indicate a single
bar at the bottom of each window while the “85” is displayed.

4. From the normal mode steady state, press and release the LOWER
ALARM LIMIT button. Begin rotating the control knob CCW within
3 seconds. Verify that the SpO 2% display reduces to a minimum of “20”.
Rotate the control knob clockwise (CW) and verify that the SpO2 %
display cannot be raised past the upper alarm limit setting of “85”.

5. Press the UPPER ALARM LIMIT button two times rapidly (twice within
3 seconds). Verify that the monitor emits two beeps and the PULSE
RATE display indicates an alarm limit of “170” for 3 seconds.

6. From the normal mode steady state, press the UPPER ALARM LIMIT
button two times rapidly. Begin rotating the control knob CCW within
3 seconds. Verify that the PULSE RATE display reduces to a minimum
of “40”.

7. Press the LOWER ALARM LIMIT button two times rapidly. Verify that
the PULSE RATE display indicates an alarm limit of “40” for 3 seconds.

8. From the normal mode steady state, press the LOWER ALARM LIMIT
button two times rapidly. Rotate the control knob CCW. Verify that the
PULSE RATE display reduces to a minimum of “30”.

3-4
 Section 3: Performance Verification

9. Press the AUDIBLE ALARM OFF button (located on top of the N-3000)
and verify that the monitor emits a low-pitched beep when the button is
pressed.

10. Press the ON/STANDBY button to turn the monitor off. Verify that the
monitor emits three decreasing pitch beeps.

11. Observe the monitor front panel. Press the ON/STANDBY button. The
monitor performs the sequence described in paragraph 3.3.3.1 (Power-On
Self-Test), 3a through 3g.

12. Press and release the UPPER ALARM LIMIT button. Verify that the
SpO 2% display indicates an alarm limit of “100”.

13. Press and release the LOWER ALARM LIMIT button. Verify that the
SpO 2% display indicates an alarm limit of “85”.

14. Press the UPPER ALARM LIMIT button two times rapidly. Verify that
the PULSE RATE display indicates an alarm limit of “170”.

15. Press the LOWER ALARM LIMIT button two times rapidly. Verify that
the PULSE RATE display indicates an alarm limit of “40”.

16. Press the ON/STANDBY button to turn the monitor off.

3.3.3.3 Neonate Power-On Defaults and Alarm Limit Ranges

Note: When observing or changing default limits, a 3-second timeout is in

effect, that is, if no action is taken within 3 seconds, the monitor
automatically returns to the normal mode steady state.

1. Turn the monitor on.

2. Press the NEW PATIENT/NEONATAL button on the rear panel two

times rapidly (twice within 2 seconds).

3. Verify that the NEONATAL MODE indicator on the front panel is lit.

4. From the normal mode steady state, press and release the UPPER
ALARM LIMIT button. Verify that the SpO2 % display indicates an
alarm limit of “95” for 3 seconds. Verify that the other displays indicate a
single bar at the top of each window while the “95” is displayed.

5. From the normal mode steady state, press and release the UPPER
ALARM LIMIT button. Begin rotating the control knob CCW within
3 seconds. Verify that the SpO 2% display reduces to a minimum of “80”.

6. From the normal mode steady state, press and release the LOWER
ALARM LIMIT button. Verify that the SpO2 % display indicates an
alarm limit of “80”. Verify that the other displays indicate a single bar at
the bottom of each window while the “80” is displayed.

7. From the normal mode steady state, press and release the LOWER
ALARM LIMIT button. Rotate the control knob CCW. Verify that the
SpO 2% display reduces to a minimum of “20”. Rotate the knob CW to
verify that the lower alarm limit cannot be raised past the upper alarm
limit of 80.

3-5
Section 3: Performance Verification

8. Press the UPPER ALARM LIMIT button two times rapidly (twice within
3 seconds). Verify that the PULSE RATE display indicates an alarm
limit of “190”.

9. Press the LOWER ALARM LIMIT button twice rapidly. Verify that the
PULSE RATE display indicates an alarm limit of “90”.

10. Press the AUDIBLE ALARM OFF button and verify that the monitor
emits a beep when the button is pressed.

11. Press the ON/STANDBY button to turn the monitor off.

12. Press the ON/STANDBY button to turn the monitor on. The monitor
performs the sequence described in 3.3.3.1.

Note: The “NEO” indicator will not be lit.

13. Press and release the UPPER ALARM LIMIT button. Verify that the
SpO 2% display indicates an alarm limit of “100”.

14. Press and release the LOWER ALARM LIMIT button. Verify that the
SpO 2% display indicates an alarm limit of “85”.

15. Press the ON/STANDBY button to turn the monitor off.

This completes the power-up tests.

3.3.4 Operation with a Pulse Oximeter Tester

Operation with an SRC-2 pulse oximeter tester includes the following tests.

• 3.3.4.1 Alarms
• 3.3.4.2 Alarm Silence
• 3.3.4.3 Alarm Volume Control
• 3.3.4.4 Volume Control
• 3.3.4.5 Dynamic Operating Range

Note: This section is written using Nellcor Puritan Bennett factory-set

defaults. If your institution has preconfigured custom defaults, those
values will be displayed. Factory defaults can be reset using the
service mode procedure described in Paragraph 4.3.11, Menu Item
20, Reset to Factory Defaults, or the configuration mode procedure
described in paragraph 4.2.8.6.

3.3.4.1 Alarms

1. Connect the SRC-2 pulse oximeter tester to the sensor input cable and
connect the cable to the monitor. Set the SRC-2 as follows:

SWITCH POSITION

RATE 38
LIGHT LOW
MODULATION HIGH
MODE LOC/RCAL 63

3-6
 Section 3: Performance Verification

2. Press and release the ON/STANDBY button to turn the monitor on. After
the normal power-up sequence, verify that the SpO2 % and PULSE RATE
displays initially indicate zeroes.

Note: The pulse bar may occasionally indicate a step change as the
monitor is in the pulse search mode.

3. Verify the following monitor reaction:

a. The pulse bar begins to track the artificial pulse signal from the
SRC-2.

b. After at least five pulses, the monitor displays a saturation and

pulse rate within the following tolerances:

Oxygen Saturation Range 79 to 83%

Pulse Rate Range 37 to 39 bpm

c. The pulse “beep” will be heard.

d. The audio alarm will sound and both the SpO 2% and PULSE RATE
display will flash, indicating both parameters have violated the
default alarm limits. To silence the alarm, continue with the
following paragraph.

3.3.4.2 Alarm Silence

After completing paragraph 3.3.4.1:

1. Press and hold the AUDIBLE ALARM OFF button on the top of the
monitor. The alarm is silenced. The PULSE RATE display indicates “60”
and the AUXILIARY display indicates “SEC” while the AUDIBLE
ALARM OFF button is pressed.

2. Release the AUDIBLE ALARM OFF button. Verify the following:

a. The alarm remains silenced.

b. The AUDIBLE ALARM OFF indicator lights.

c. The SpO2 % and PULSE RATE displays resume flashing.

d. The pulse tone is still audible.

e. The audio alarm returns approximately 60 seconds after the

AUDIBLE ALARM OFF button is released.

3. Press and hold the AUDIBLE ALARM OFF button. Rotate the control
knob CCW until the PULSE RATE display indicates “30 SEC”. Rotate
the control knob clockwise (CW) and verify that the displays indicate
60 SEC, 90 SEC, 120 SEC, and OFF. Release the button when the
display indicates “OFF”. Verify that the AUDIBLE ALARM OFF
indicator flashes.

4. Wait approximately 3 minutes. Verify that the alarm does not return.
After 3 minutes, the alarm silence reminder beeps three times, and will
continue to do so at 3-minute intervals.

3-7
Section 3: Performance Verification

3.3.4.3 Alarm Volume Control

After completing paragraph 3.3.4.2:

1. Press and hold the AUDIBLE ALARM OFF button on the top of the
monitor. Verify the following:

a. “OFF” is displayed for approximately 3 seconds.

b. After 3 seconds, a steady tone is heard at the default alarm volume

setting, the PULSE RATE display indicates “VOL”, and the
AUXILIARY display indicates the current default setting.

2. While continuing to hold the AUDIBLE ALARM OFF button, rotate the
control knob CCW to decrease the alarm volume setting to a minimum
value of 1. The alarm tone should still be audible. Rotate the control
knob CW to increase the alarm volume setting to a maximum value of
10. Rotate the knob until a comfortable audio level is attained.

3. Release the AUDIBLE ALARM OFF button. The tone will stop.

3.3.4.4 Pulse Tone Volume Control

1. Rotate the control knob CW and verify that the beeping pulse tone sound
level increases.

2. Rotate the control knob CCW and verify that the beeping pulse tone can
be turned off completely. Rotate the knob CW until a comfortable audio
level is attained.

3.3.4.5 Dynamic Operating Range

The following test sequence will verify proper monitor operation over a wide
range of input signals.

Note: The N-3000 pulse qualification may occasionally reject some pulses
from the SRC-2 pulse oximeter tester. This is indicated by the
missing audible pulse tone and the illuminated PATIENT MOTION
indicator.

1. Verify that the monitor is still displaying saturation and that pulse
information is in compliance with the SRC-2 tolerance. Both displays are
still flashing due to alarm limit violation.

Oxygen Saturation Range: 79 to 83%

Pulse Rate Range: 37 to 39 bpm

2. Ensure the MODULATION switch on the SRC-2 is set to HIGH and

verify that after a few seconds the monitor indications are within the
tolerances listed in step 1.

3. Move the MODULATION switch to LOW and verify that after a few
seconds the monitor indications are within the tolerances listed in step 1.

4. Move the LIGHT switch to HIGH 2 and verify that after a few seconds
the monitor indications are within the tolerances listed in step 1.

5. Move the MODULATION switch to HIGH and verify that after a few
seconds the monitor indications are within the tolerances listed in step 1.

3-8
 Section 3: Performance Verification

6. Move the RATE switch to 112 bpm. After approximately 30 seconds,

verify that the PULSE RATE display has stopped flashing and that the
display indications are within the tolerances shown below:

Oxygen Saturation Range: 79 to 83%

Pulse Rate Range: 110 to 114 bpm

Note: If the unit has been configured for the “latching alarm ON”
setting, the HEART/PULSE RATE display continues to flash,
despite the pulse rate being within upper and lower alarm
limits. Press the AUDIBLE ALARM OFF button to stop the
flashing. Refer to paragraph 4.3.13 to place the unit in the
“latching alarm OFF” setting.

7. Move the MODULATION switch to LOW and verify that after a few
seconds the monitor indications are within the tolerances listed in step 6.

8. With the LIGHT switch set to HIGH 2, verify that after a few seconds
the monitor indications are within the tolerances listed in step 6.

9. Move the MODULATION switch to HIGH and verify that after a few
seconds the monitor indications are within the tolerances listed in step 6.

10. Move the LIGHT switch to LOW and verify that after a few seconds the
monitor indications are within the tolerances listed in step 6.

11. Move the MODULATION switch to LOW and verify that after a few
seconds the monitor indications are within the tolerances listed in step 6.

12. Move the RATE switch to 201 bpm. After approximately 30 seconds,
verify that the PULSE RATE display is flashing and the display
indications are within the tolerances shown below:

Oxygen Saturation Range: 79 to 83%

Pulse Rate Range: 195 to 207 bpm

13. Move the MODULATION switch to HIGH and verify that after a few
seconds the monitor indications are within the tolerances listed in
step 12.

14. Move the LIGHT switch to HIGH 1 and verify that after a few seconds
the monitor indications are within the tolerances listed in step 12.

15. Move the MODULATION switch to LOW and verify that after a few
seconds the monitor indications are within the tolerances listed in
step 12.

16. Move the LIGHT switch to HIGH 2 and verify that after a few seconds
the monitor indications are within the tolerances listed in step 12.

17. With the MODULATION switch to LOW, verify that after a few seconds
the monitor indications are within the tolerances listed in step 12.

18. Turn the N-3000 off. Disconnect the tester from the cable.

3-9
Section 3: Performance Verification

3.3.5 Normal Operation

The following tests are an overall performance check of the system:

• LED Excitation Test

• Operation with a Live Subject
• Serial Interface Test

3.3.5.1 LED Excitation Test

This procedure uses normal system components to test circuit operation. A

Nellcor Puritan Bennett Oxisensor II oxygen transducer, model D-25, is used
to examine LED intensity control. The red LED is used to verify intensity
modulation caused by the LED intensity control circuit.

1. Connect the monitor to an AC power source through the SPS power

supply.

2. Connect an SCP-10 sensor input cable to the monitor.

3. Connect a D-25 sensor to the sensor input cable.

4. Press the ON/STANDBY button to turn the monitor on.

5. Leave the sensor open with the LEDs and photodetector visible.

6. After the monitor completes its normal power-up sequence, verify that
the sensor LED is brightly lit.

7. Slowly move the sensor LED in proximity to the photodetector element of

the sensor. Verify, as the LED approaches the optical sensor, that the
LED intensity decreases.

8. Open the sensor and notice that the LED intensity increases.

9. Repeat step 7 and the intensity will again decrease. This variation is an
indication that the microprocessor is in proper control of LED intensity.

10. Turn the N-3000 off.

3.3.5.2 Operation with a Live Subject

Patient monitoring involves connecting the monitor to a live subject for a

qualitative test.

1. Connect the N-3000 to an AC power source.

2. Connect an SCP-10 sensor input cable to the monitor.

3. Connect a Nellcor Puritan Bennett Durasensor oxygen transducer, model

DS-100A, to the sensor input cable.

4. Clip the DS-100A to the subject as recommended in the sensor directions

for use.

5. Press the ON/STANDBY button to turn the monitor on.

6. The monitor should stabilize on the subject’s physiological signal in

about 10 to 15 seconds. Verify that the saturation and pulse rates are
reasonable for the subject.

3-10
 Section 3: Performance Verification

3.3.5.3 Serial Interface Test

The communications submodule of the N-3000, using an asynchronous,

EIA-232 communications format, allows communications between the N-3000
and a PC, via the 6-pin connector on the rear panel of the N-3000, as
illustrated in Figure 3-2. An EIA-232 cable and detailed directions for use are
available by contacting your local Nellcor Puritan Bennett representative.

Figure 3-2: Serial Port Interface

The serial port can also be used to provide remote monitoring of alarms when
configured as explained in paragraph 4.4, Alarm Active Function.

The two configurable options of serial data interface are RS-232 and EIA-422.
The N -3000 is shipped with the RS-232 setting. To change the settings, refer
to paragraph 6.5.1.

Perform the following procedure to test the serial port voltages.

1. Connect the monitor to an AC power source through the SPS power

supply and turn the monitor on. (The serial port is functional only when
the N-3000 is operated from an AC power source.)

2. Connect a 6-pin miniature connector adapter to the serial interface port.

3. Set up the DMM as follows:

Function: VDC
Range: 10 V

4. Connect the DMM negative lead to connector pin 4 (GND).

3-11
Section 3: Performance Verification

5. Connect the DMM positive lead to the following pins and verify the
voltage values listed in Table 3-1.

1 2
3 4
5 6

Serial Port Connector

External Pin Locations

Table 3-1: Serial Port Voltages

Pin Line Voltage

1 DTR 7.5 ± 2.5
2 DSR 0.0 ± 0.4
3 TXD -7.5 ± 2.5
4 GND 0.0 ± 0.4
5 RXD 0.0 ± 0.4
6 Alarm Active* 0.0 ± 0.4 or
3.3 ± 0.4

*Allows alarm activity to be monitored from a location away

from the N-3000 (refer to paragraph 4.4).

Connections between the N-3000 serial port and an external PC are as

indicated in Figure 3-3.

DIN DSR
6 9-Pin
DTR DSR CTS
1 8
DSR DTR
2 1 2 4
TX RX
4 3 3 2
GND GND
6 5 4 5
RX TX
5 3
6 ALARM ACTIVE 1
Spares 7
9
Shield

Shield connected to shell

Figure 3-3: N-3000 to External PC Connections

3.4 SAFETY TESTS

N-3000 safety tests consist of:

• Ground Integrity
• Electrical Leakage

3-12
 Section 3: Performance Verification

3.4.1 Ground Integrity

This test verifies the integrity of the power cord ground wire from the AC
plug and connection with the SPS external power supply chassis ground.

1. Configure the electrical safety analyzer as follows:

Function: Ground resistance test

Range: mΩ

2. Connect the monitor’s AC plug to the analyzer as recommended by the

analyzer operating instructions.

3. Connect the analyzer “resistance” input lead to the grounding lug on the
rear panel of the external power supply. Verify that the analyzer
indicates 150 milliohms or less.

3.4.2 Electrical Leakage

The following tests verify the electrical leakage of the monitor.

• Chassis Source Current

• Patient Source Current
• Patient Sink Current

3.4.2.1 Chassis Source Current

This test is in compliance with IEC 601.1 and AAMI Standard ES1,
Paragraph 3.3.1, Chassis Source Current, between the power ground and
(part b), exposed conductive hardware.

1. Configure the electrical safety analyzer as follows:

Function: Leakage
Range: µA

2. Connect the monitor AC plug to the electrical safety analyzer as

recommended by the analyzer operating instructions.

3. Connect the electrical safety analyzer “leakage” input lead to the

monitor’s SPS external power supply grounding lug.

The analyzer leakage indication must not exceed 100 microamps at

100-120 VAC or 500 microamps at 220-240 VAC for the following AC
power configurations while the monitor is turned on or while turned off.

AC LINE POWER LINE

POLARITY GROUND CABLE

Normal Normal
Reverse Normal
Reverse Open
Normal Open

3-13
Section 3: Performance Verification

3.4.2.2 Patient Source Current

This test is in compliance with AAMI Standard ES1, Paragraph 3.3.2. Patient
Source Current is measured between any individual patient connection and
power (earth) ground.

1. Configure the electrical safety analyzer as follows:

Function: Leakage
Range: µA

2. Connect the monitor AC plug to the electrical safety analyzer as

recommended by the analyzer operating instructions for patient source
current.

3. Connect the electrical safety analyzer leakage input lead to the monitor’s
sensor input connector.

The analyzer leakage indication must not exceed 10 microamps for all of
the following AC power configurations with the monitor on.

AC LINE POWER LINE

POLARITY GROUND CABLE

Normal Normal
Reverse Normal
Reverse Open
Normal Open

3.4.2.3 Patient Sink Current

This test is in compliance with AAMI Standard ES1, Paragraph 4.4. Patient
sink current is measured in a patient connection if a source of 240 volts,
50 Hz (or 120 volts, 60 Hz) with respect to power (earth) ground, is connected
to that patient connection.

1. Configure the electrical safety analyzer as follows:

Function: Leakage
Range: µA

2. Connect the monitor AC plug to the electrical safety analyzer as

recommended by the operating instructions for patient sink current.

3. Connect the electrical safety analyzer leakage input lead to the monitor’s
sensor input.

The analyzer leakage indication must not exceed 50 microamps for

240 volts (10 microamps for 120 volts) for the following AC power
configurations with the monitor on.

AC LINE POWER LINE

POLARITY GROUND CABLE

Normal Normal
Normal Open

3-14
 Section 3: Performance Verification

3.5 SPO2 TESTS

The following tests can be used to verify, analyze, and troubleshoot the SpO 2
circuitry of the N-3000:

• RCAL Circuit Test

• LED Drive Tests

The tests require use of the SRC-2 tester and the service mode configuration,
as detailed in paragraph 4.3.

3.5.1 RCAL Circuit Test

1. Connect an SRC-2 pulse oximeter tester to the sensor input cable and
connect the cable to the monitor.

2. Set the SRC-2 as follows:

SWITCH POSITION

RATE 112
LIGHT LOW
MODULATION OFF
MODE LOC/RCAL 63

3. Enter the service mode steady state, as instructed in paragraph 4.3.

4. Select menu item 30 by rotating the knob until “30” appears in the
SpO 2% display. Press the UPPER ALARM LIMIT button.

5. The RCAL value “63” is displayed in the PULSE RATE display.

6. Set the SRC-2 RCAL/Mode switch to REM/RCAL 64. The RCAL value
“64” is displayed in the PULSE RATE display.

7. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

3.5.2 LED Drive Tests

1. Connect an SRC-2 pulse oximeter tester to the sensor input cable and
connect the cable to the monitor.

2. Set the SRC-2 as follows:

SWITCH POSITION

RATE 112
LIGHT LOW
MODULATION OFF
MODE REM/RCAL 63

3. If you are not already in the service mode, enter the service mode steady
state, as instructed in paragraph 4.3.

4. Select menu item 33 by rotating the knob until “33” appears in the
SpO 2% display. Press the UPPER ALARM LIMIT button.

5. The SpO2 IR LED drive value “170” is displayed in the PULSE RATE
display. The IR indicator on the SRC-2 is illuminated.

3-15
Section 3: Performance Verification

6. Rotate the knob to adjust the IR LED drive level indicated in the PULSE
RATE display to 255.

7. While watching the IR indicator on the SRC-2, confirm the setting by

pressing the UPPER ALARM LIMIT button. The LED intensity should
increase.

8. Rotate the knob to adjust the IR LED drive level indicated in the PULSE
RATE display to 0.

9. Press the UPPER ALARM LIMIT button. The IR LED should turn off.

10. Rotate the knob to adjust the IR LED drive level indicated in the PULSE
RATE display to 170.

11. Press the UPPER ALARM LIMIT button. The IR LED intensity should
increase.

12. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

13. Select menu item 34 by rotating the knob until “34” appears in the
SpO 2% display. Press the UPPER ALARM LIMIT button.

14. The SpO2 red LED drive value “170” is displayed in the PULSE RATE
display. The IR indicator on the SRC-2 is illuminated.

15. Rotate the knob to adjust the red LED drive level indicated in the
PULSE RATE display to 255.

16. While watching the RED indicator on the SRC-2, confirm the setting by
pressing the UPPER ALARM LIMIT button. The LED intensity should
increase.

17. Rotate the knob to adjust the red LED drive level indicated in the
PULSE RATE display to 0.

18. Press the UPPER ALARM LIMIT button. The RED indicator should turn
off.

19. Rotate the knob to adjust the red LED drive level indicated in the
PULSE RATE display to 170.

20. Press the UPPER ALARM LIMIT button. The RED indicator intensity
should increase.

21. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

22. Press the ON/STANDBY button to turn the N-3000 off.

3-16
 Section 3: Performance Verification

3.6 PIEZO SPEAKER TEST

The following test verifies that the piezo power loss alarm speaker sounds an
alarm when the N-3000 loses power.

WARNING: Before attempting to open or disassemble the N-3000,

disconnect the power cord from the N-3000.

Caution: Observe ESD (electrostatic discharge) precautions when

working within the unit.

1. Ensure that the N-3000 is turned off.

2. Disconnect the monitor from the SPS power supply.

3. Set the N-3000 upside down facing you, as shown in Figure 3-4.

Battery cover

Squeeze
Battery cover
fasteners

NE
Squeeze
LLC
OR
Sym
pho
ny
N-3
000

Figure 3-4: Battery Cover Removal

4. Using a small, Phillips-head screwdriver, loosen the two battery cover

retaining fasteners securing the battery compartment cover.

5. Gently squeeze the battery cover sides in the middle as you swing the
cover open (it is hinged on the right with three tabs that extend into slots
on the chassis).

6. Lift the battery out of the compartment, as shown in Figure 3-5. It may
be necessary to use the edge of a flat tip screwdriver to gently pry the
battery loose.

3-17
Section 3: Performance Verification

Battery cover

Battery

Power
connector

NE
LLC
OR
Sym
pho
ny
N-3
000

Battery bracket

Figure 3-5: Speaker Test

7. Turn the monitor on by pressing the ON/STANDBY button.

8. When the power-on self-test is complete, disconnect the power connector

from the battery. Verify that a shrill, beeping alarm is emitted from the
speaker. If no alarm sounds, check the functionality of the lithium
backup battery as indicated in paragraph 4.3.9, menu item 18.2 of the
service mode. The battery should measure approximately 3 volts. If the
battery is good, replace the UIF PCB as indicated in paragraph 6.8.

9. Reconnect the power connector to the battery. The alarm is silenced and
the monitor powers back on.

10. Turn the monitor off by pressing the ON/STANDBY button.

11. Replace the battery in the battery bracket and reconnect the battery
cover.

3-18
SECTION 4: CONFIGURATION MODE, SERVICE MODE, AND ALARM
ACTIVE FUNCTION
4.1 Introduction
4.2 Configuration Mode
4.3 Service Mode
4.4 Alarm Active Function

4.1 INTRODUCTION

This section discusses use of the configuration mode to reconfigure power-on

default values, the service mode to identify and correct monitor difficulties,
and the alarm active function.

4.2 CONFIGURATION MODE

The following paragraphs describe how to enter the N-3000 configuration

mode and change factory power-on default settings.

The N -3000 cannot enter the configuration mode while it is stacked unless
the N-3100 is in the configuration mode or is turned off. If both instruments
are in the configuration mode, the N-3000 knob may be used to scroll to the
desired menu item and adjust the settings of the N-3100.

Use the following procedure to enter configuration mode:

1. If the monitor is on, turn it off.

2. While simultaneously pressing both UPPER and LOWER ALARM

LIMIT buttons, turn the monitor on. Continue to press both buttons until
“CFG” begins flashing in the AUXILIARY display.

3. Release the UPPER and LOWER ALARM LIMIT buttons.

4. Press the PRINT button. “CFG” stops flashing and remains displayed in
the AUXILIARY display. (If the PRINT button is not pressed within
15 seconds after “CFG” begins flashing, the monitor will turn off
automatically.)

You are now in configuration mode steady state. The N-3000 automatically
powers down if no action is taken for approximately 2 minutes.

After changing or viewing a default setting, you can return to the

configuration mode steady state by allowing the display to timeout
(3 seconds).

To exit the configuration mode, turn the monitor off by pressing the
ON/STANDBY button. Default settings take place when the monitor is
turned off. Default settings also take place if the N-3000 powers down due to
the 2-minute timeout.

4-1
Section 4: Configuration Mode, Service Mode, and Alarm Active Function

Note: While changing default limits, there must be some user interaction
with the monitor within a 3-second period or the monitor will return
to configuration mode steady state operation.

Table 4-1 lists the default settings that can be configured and the respective
entry procedures to access the settings. Methods used to change the default
settings are detailed in paragraphs 4.2.1 through 4.2.8.

Table 4-1: Configuration Mode Menu

Power on Default Button Press Procedure from Paragraph

Setting Configuration Mode Steady State Described
Adult/Neonatal Mode NEW PATIENT/NEONATAL button 4.2.1
twice
SpO 2 Upper Alarm Limit UPPER ALARM LIMIT button 4.2.2
SpO 2 Lower Alarm Limit LOWER ALARM LIMIT button 4.2.3
Pulse Rate Upper Alarm UPPER ALARM LIMIT button twice 4.2.4
Limit
Pulse Rate Lower Alarm LOWER ALARM LIMIT button twice 4.2.5
Limit
Alarm Volume ALARM SILENCE button (press and 4.2.6
hold for 3 seconds before turning
knob)
Alarm Silence Duration ALARM SILENCE button (press and 4.2.7
hold; turn knob within 3 seconds)
Configuration Menu UPPER/LOWER ALARM LIMIT 4.2.8
buttons simultaneously

Note: To change neonate default limits, enter the neonatal mode from
configuration mode steady state by pressing the NEW
PATIENT/NEONATAL button twice within 2 seconds. Change the
desired limit using the same method as adult default limits.

When an SpO2 or pulse rate default limit has been changed, a decimal point
will appear after the displayed limit until the configuration mode is exited.

4.2.1 Adult/Neonatal Mode Default

The mode (adult or neonatal) that the monitor is in when exiting the
configuration mode, becomes the power-on default.

To change from a power-on default of adult mode to a power-on default of

neonatal mode, enter the configuration mode steady state. Press the NEW
PATIENT/NEONATAL button twice within 2 seconds and then power-down
by pressing the ON/STANDBY button.

4-2
 Section 4: Configuration Mode, Service Mode, and Alarm Active Function

4.2.2 Default SpO2 Upper Alarm Limit

1. From the configuration mode steady state, press and release the UPPER
ALARM LIMIT button. The current default value is displayed in the
SpO 2% display. Dashes appear in the PULSE RATE display (the upper
horizontal segments of the display), indicating that the monitor is in the
“set SpO2 upper alarm limit” mode.

2. To change the upper alarm limit value, rotate the knob on top of the
monitor. You cannot decrease the value lower than the current SpO 2
lower alarm limit default setting. The SpO2 upper alarm limit cannot be
set higher than 100.

3. Return to configuration mode steady state.

Note: If you press the LOWER ALARM LIMIT button before the
3-second timeout, you can then change the SpO2 lower alarm
limit default. If you press the UPPER ALARM LIMIT button,
you can then change the pulse rate upper alarm limit default.
This method can also be used while setting the other default
alarm limits.

4.2.3 Default SpO2 Lower Alarm Limit

1. From the configuration mode steady state, press and release the LOWER
ALARM LIMIT button. The current default value is displayed in the
SpO 2% display.

2. To change the lower alarm limit default value, rotate the knob on top of
the monitor. You cannot increase the value higher than the current SpO 2
upper alarm limit setting. The SpO2 default lower alarm limit cannot be
set lower than 80.

3. Return to configuration mode steady state.

4.2.4 Default Pulse Rate Upper Alarm Limit

1. From the configuration mode steady state, press the UPPER ALARM
LIMIT button twice within 3 seconds. The current default value is
displayed in the PULSE RATE display. Dashes appear in the SpO2 %
display (the upper horizontal segments of the display), indicating that
the monitor is in the “set pulse rate upper alarm limit” mode.

2. To change the upper alarm limit default value, rotate the knob on top of
the monitor. You cannot decrease the value lower than the current pulse
rate lower alarm limit default setting. The pulse rate default upper
alarm limit cannot be set higher than 250.

3. Return to configuration mode steady state.

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Section 4: Configuration Mode, Service Mode, and Alarm Active Function

4.2.5 Default Pulse Rate Lower Alarm Limit

1. From the configuration mode steady state, press the LOWER ALARM
LIMIT button twice within 3 seconds. The current default value is
displayed in the PULSE RATE display.

2. To change the lower alarm limit value, rotate the knob CW to increase,
or CCW to decrease. You cannot increase the value higher than the
current pulse rate upper limit setting. The pulse rate lower alarm limit
cannot be set lower than 30.

3. Return to configuration mode steady state.

4.2.6 Default Alarm Volume

Perform the following steps to adjust the default alarm volume:

1. From the configuration mode steady state, press and hold the AUDIBLE
ALARM OFF button. After 3 seconds, a continuous tone at the current
volume setting is emitted. “VOL” is displayed in the PULSE RATE
display, and the current default alarm setting (a number from 1 to 10) is
displayed in the SpO2 % display.

2. While continuing to hold the AUDIBLE ALARM OFF button, turn the
control knob on the top of the monitor CW to increase the default
volume, CCW to decrease the default volume.

3. Release the AUDIBLE ALARM OFF button and the monitor returns to
the configuration mode steady state.

4.2.7 Default Alarm Silence Duration

The default alarm silence duration may also be adjusted while in the
configuration mode. To do so:

1. From the configuration mode steady state, press and hold the AUDIBLE
ALARM OFF button for 3 seconds or less. The current default setting for
the alarm silence duration appears in the PULSE RATE display. The
SpO 2% display indicates “CFG”, while the AUXILIARY display indicates
“SEC” (seconds).

Note: Pressing the AUDIBLE ALARM OFF button for more than
3 seconds without turning the knob, causes the N-3000 to enter
the “Default Alarm Volume” mode as described in paragraph
4.2.6.

2. Use the control knob on the top of the N-3000 to adjust the default alarm
silence duration. Alarm silence duration choices are 30 SEC, 60 SEC,
90 SEC, and 120 SEC.

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 Section 4: Configuration Mode, Service Mode, and Alarm Active Function

4.2.8 Configuration Menu

The configuration menu allows you to configure the functions listed in Table
4-2. After accessing a menu item by pressing the UPPER ALARM LIMIT
button, if the knob is not turned and no button is pressed for a period of time
equal to the “timeout” as listed in the table, you will automatically return to
the configuration menu steady state. The last setting displayed for the menu
item will become the default setting.

Table 4-2: Configuration Menu

Menu Paragraph
Number Configurable Setting Described Timeout
0 Pulse tone volume 4.2.8.1 3 seconds
1 UIF software version report 4.2.8.2 10 seconds
2 SpO 2 software version report 4.2.8.3 10 seconds
3 Set baud rate 4.2.8.4 3 seconds
4 Trend type 4.2.8.5 3 seconds
5 Reset to factory defaults 4.2.8.6 N/A

To access the configuration menu from the configuration mode steady state,
press the UPPER and LOWER ALARM LIMIT buttons simultaneously. The
SpO 2% display indicates the menu number (0 through 5) and the PATIENT
MOTION indicator is illuminated to indicate the monitor is in the
configuration menu steady state.

Rotate the knob on top of the N-3000 to access the desired menu number.
Press the UPPER ALARM LIMIT button to configure the displayed item,
using the procedures listed in paragraphs 4.2.8.1 through 4.2.8.6.

To exit the configuration menu steady state and return to the configuration
mode steady state, press the LOWER ALARM LIMIT button or, if there is no
knob or button activity for 15 seconds, you will automatically return to the
configuration mode steady state. You may also exit by turning the monitor
off.

4.2.8.1 Pulse Tone Volume

Menu item number “0” allows you to determine the default volume (1 through
10) for the pulse tone.

1. From the configuration menu steady state, rotate the knob until “0” is
displayed in the SpO2 % display. Press the UPPER ALARM LIMIT
button.

2. The current default pulse tone volume setting is displayed in the PULSE
RATE display. An audio tone sounds at the current volume setting
Rotate the knob CW or CCW to display the desired power-on default
volume level (1 through 10).

3. Press the LOWER ALARM LIMIT BUTTON to return to the

configuration menu steady state.

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Section 4: Configuration Mode, Service Mode, and Alarm Active Function

4.2.8.2 UIF Software Version Report

1. From the configuration menu steady state, rotate the knob until “1” is
displayed in the SpO2 % display. Press the UPPER ALARM LIMIT
button.

2. The UIF software version number is the left-most digit in the SpO 2%
display. The next two digits in the SpO2 % display represent the major
software revision number. The minor software revision number is
displayed in the PULSE RATE display. Press the LOWER ALARM
LIMIT BUTTON to return to the configuration menu steady state.

4.2.8.3 SpO 2 Software Version Report

1. From the configuration menu steady state, rotate the knob until “2” is
displayed in the SpO2 % display. Press the UPPER ALARM LIMIT
button.

2. The SpO2 software version number is the left-most digit in the SpO2 %
display. The next two digits in the SpO2 % display represent the major
software revision number. The minor software revision number is
displayed in the PULSE RATE display. Press the LOWER ALARM
LIMIT BUTTON to return to the configuration menu steady state.

4.2.8.4 Set Serial Port Baud Rate

1. From the configuration menu steady state, rotate the knob until “3” is
displayed in the SpO2 % display. Press the UPPER ALARM LIMIT
button.

Note: Baud rates should not exceed 19,200 in RS-232 mode (use EIA-
422 mode). Refer to paragraph 6.5.1 to change the
communication mode settings.

2. The current baud rate, in thousands, is displayed in the PULSE RATE

display. To change the default baud rate setting, rotate the knob until
the desired setting is displayed.

3. Press the LOWER ALARM LIMIT button to return to the configuration

menu steady state.

4.2.8.5 Trend Type

Menu item number 4 allows you to select “5”, “10” or “20” (displayed in the
SpO 2% display) as the default trend format. Selecting “20” causes patient
trend data to be recorded every 20 seconds. Each patient parameter value
will be both the maximum and minimum data for each parameter during the
sample period. Data is stored for the most recent 24 hours of patient
monitoring. This selection is described as “Format 2” in the N-3000 operator’s
manual.

Selecting “10” causes patient trend data to be recorded every 10 seconds.

Each patient parameter value will be the average of all data samples for each
parameter during the sample period. Data is stored for the most recent 24
hours of patient monitoring. This selection is described as “Format 1” in the
N-3000 operator’s manual.

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 Section 4: Configuration Mode, Service Mode, and Alarm Active Function

Selecting “5” causes patient trend data to be recorded every 5 seconds. Each
patient parameter value will be the most recent data sample for each
parameter during the sample period. Data is stored for the most recent
12 hours of patient monitoring. This selection is described as “Format 3” in
the N-3000 operator’s manual.

1. From the configuration menu steady state, rotate the knob until “4” is
displayed in the SpO2 % display. Press the UPPER ALARM LIMIT
button.

2. “5”, “10” or “20” is displayed in the PULSE RATE display. Rotate the
knob to display the desired default trend type.

3. Press the LOWER ALARM LIMIT BUTTON to return to the

configuration menu steady state.

4.2.8.6 Reset to Factory Defaults

Menu item number 5 allows you to reset all default settings to the original
factory settings as listed in paragraph 9.6, “Factory Default Settings,” of the
Specifications section.

1. From the configuration menu steady state, rotate the knob until “5” is
displayed in the SpO2 % display.

2. Press the UPPER ALARM LIMIT button to reset to factory defaults.

Three beeps indicate that all configurable power-on default parameters,
except latching alarms enable and alarm silence reminder enable, are
now set to their factory default values. You are automatically returned to
the configuration menu steady state.

4.3 SERVICE MODE

The service mode allows the technician to go through a series of tests to

determine monitor functionality and to access the error log report.

The service modes cannot be accessed by the N-3000 while it is stacked with
an active N-3100. If operating in the stacked configuration, disconnect the
N-3000 from the N- 3100 or turn the N-3100 off before entering the service
mode.

Use the following procedures to place the monitor into the service mode:

1. If the monitor is on, turn it off.

2. While simultaneously holding down the UPPER and LOWER ALARM

LIMIT buttons and the PRINT button, press and release the
ON/STANDBY button. Continue to press and hold the UPPER and
LOWER ALARM LIMIT and PRINT buttons while the monitor performs
the power-on self-test.

3. When “SEr” begins flashing in the AUXILIARY display, release the

UPPER and LOWER ALARM LIMIT and PRINT buttons.

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Section 4: Configuration Mode, Service Mode, and Alarm Active Function

4. Press the PRINT button. You must press this button within 15 seconds
or the monitor will turn off automatically. You are now in service mode
steady state.

Note: Failure errors (refer to Troubleshooting section for an

explanation of failure errors and error codes) may be
encountered by the N-3000 upon entering the service mode. The
N-3000 will automatically access the menu item used to correct
this situation.

If a user-correctable error code (a code beginning with “0”) is

displayed while in the service mode, press the LOWER ALARM
LIMIT button to clear the error.

• “SEr” stops flashing and is continuously displayed.

• The number “1” is indicated in the SpO2 % display.

• The PATIENT MOTION indicator is lit, indicating that you are in

the service mode steady state, with access to the main menu as
indicated in Table 4-3.
MOTION

5. Use the knob to move from one main menu item to the next.

While in service mode, the UPPER and LOWER ALARM LIMIT buttons
are used as enter and exit buttons, respectively. You must press the
UPPER ALARM LIMIT button to select a main menu item and move to
the submenu level.

6. When you have scrolled to the desired menu item, press the UPPER
ALARM LIMIT button. The PATIENT MOTION indicator goes out and
the PULSE SEARCH indicator illuminates.
PULSE SEARCH

This indicates that you are now in a submenu of the selected main menu
item. Use the knob to move from one submenu item to the next. Not all
menu items have submenu selections.

7. To return to the service mode steady state from a menu item, press the
LOWER ALARM LIMIT button. (Menu item 3, Button Test, is an
exception; it is exited by rotating the knob.)

8. To exit the service mode, power-down the monitor by pressing the

ON/STANDBY button. The N-3000 is automatically powered down if no
action is taken for approximately 5 minutes.

Main menu items available from the service mode steady state are discussed
in numerical order as indicated in Table 4-3.

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 Section 4: Configuration Mode, Service Mode, and Alarm Active Function

Table 4-3: Service Mode Steady State - Main Menu

Menu Paragraph
No. Type of Report/Test Described
1 Software Version Report 4.3.1
2 Knob and Lamp Test 4.3.2
3 Button Test 4.3.3
4 Speaker Test 4.3.4
5 Internal Configuration Code (ICC) Report 4.3.5
6 Total Operating Hours Report 4.3.6
7 Error Log Record 1 4.3.7
8 Error Log Record 2 4.3.7
9 Error Log Record 3 4.3.7
10 Error Log Record 4 4.3.7
11 Error Log Record 5 4.3.7
12 Error Log Record 6 4.3.7
13 Error Log Record 7 4.3.7
14 Error Log Record 8 4.3.7
15 Error Log Record 9 4.3.7
16 Error Log Record 10 4.3.7
17 Instrument Identification (IID) Report 4.3.8
18 Power Management and Battery Status 4.3.9
19 Persistent Time Sense Report 4.3.10
20 Reset to Factory Defaults 4.3.11
21 Initial Cluster Instrument Number Report 4.3.12
22 Enable/Disable Latching Alarms 4.3.13
23 Enable/Disable Alarm Silence Reminder 4.3.14
25 Dump EEPROM Data 4.3.15
28 Enable/Disable Battery Charge Circuit 4.3.16
29 Instrument Compatibility Report 4.3.17
30 SpO 2 RCAL Report 4.3.18
31 SpO 2 IR and Red Offset Report 4.3.19
32 SpO 2 Corrected IR and Red Signals Report 4.3.20
33 SpO 2 IR LED Drive Test 4.3.21
34 SpO 2 Red LED Drive Test 4.3.22
35 SpO 2 DM-Gain Test 4.3.23
36 SpO 2 P-Gain Test 4.3.24
37 Set SpO 2 Analog Test Mode 4.3.25
38 SpO 2 A/D-Cal Line Test 4.3.26
39 SpO 2 Enable Automatic Operation 4.3.27
60 Set Serial Port Baud Rate 4.3.28
61 Serial Port Loop Back Test 4.3.29
62 Serial Port Transmit Test 4.3.30
70 Nellcor Puritan Bennett Internal Test - DO NOT USE

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Section 4: Configuration Mode, Service Mode, and Alarm Active Function

4.3.1 Menu Item 1: Software Version Report

This report identifies the software versions of the UIF and SpO2 modules.

1. From the service mode steady state, select menu item 1 by rotating the
Nellcor Puritan Bennett knob until “1” appears in the SpO2 % display.
Press the UPPER ALARM LIMIT button. A “1.0” appears in the SpO 2%
display.

The UIF software version number is the left-most digit in the PULSE
RATE display. The next two digits in the PULSE RATE display
represent the major software revision number. The minor software
revision number is displayed in the AUXILIARY display.

2. Rotate the knob to change the number in the SpO 2% display to “1.1”. The
SpO 2 software version number is the left-most digit in the PULSE
RATE display. The next two digits in the PULSE RATE display
represent the major software revision number. The minor software
revision number is displayed in the AUXILIARY display.

3. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.2 Menu Item 2: Knob and Lamp Test

This test verifies that indicators, front-panel lamps, and the control knob are
functional.

1. From the service mode steady state, select menu item 2 by rotating the
knob until “2” appears in the SpO 2% display. Press the UPPER ALARM
LIMIT button. All indicators light.

2. Rotate the knob CW to light each display segment, decimal, indicator,

and blip bar in a firefly pattern to verify that each lamp works.

Note: The POWER-ON indicator is not tested with this procedure. It

can be verified by turning the monitor on and off. The BATTERY
CHARGING indicator is also not tested.

3. Rotate the knob CCW to reverse the firefly pattern. Knob functionality is
verified by the even movement through the firefly pattern as the knob is
turned.

4. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.3 Menu Item 3: Button Test

This test verifies proper operation of individual buttons and button

combinations.

1. From the service mode steady state, select menu item 3 by rotating the
Nellcor Puritan Bennett knob until “3” appears in the SpO2 % display.
Press the UPPER ALARM LIMIT button. A “0” appears in the PULSE
RATE display.

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 Section 4: Configuration Mode, Service Mode, and Alarm Active Function

2. Press each of the buttons and button combinations listed below. The
corresponding number appears in the PULSE RATE display to indicate
that these buttons and button combinations are functioning correctly.

Press the following button and/or button combinations: Displayed

number:
None pressed 0
Audible alarm off 1
New patient/neonatal (rear panel) 2
Upper alarm limit 3
Lower alarm limit 4
Print 5
Upper and lower alarm limits, simultaneously 6
Upper/lower limits and print, simultaneously 7
Upper limit and audible alarm off, simultaneously 8
Lower limit and audible alarm off, simultaneously 9
Any combination not listed above 10

3. Rotate the knob CW or CCW to return to the service mode steady state.

4.3.4 Menu Item 4: Speaker Test

This test verifies that the volume control is functional and determines
whether or not there are any discontinuities or saturation conditions in the
audible output.

1. From the service mode steady state, select menu item 4 by rotating the
knob until “4” appears in the SpO 2% display. Press the UPPER ALARM
LIMIT button. A “1” appears in the PULSE RATE display and a low-
level audible tone heard.

2. Rotate the control knob CW. As the number in the PULSE RATE display
increases from 0 to 254, the volume will correspondingly increase.

3. Rotate the control knob CCW to decrease the volume.

4. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.5 Menu Item 5: Internal Configuration Code (ICC) Report

This menu item verifies whether the current monitor configuration is the
desired configuration. The ICC is the hexadecimal representation of the
instrument hardware configuration derived by the UIF processor through
internal examination of the modules and software present in the N-3000.

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Section 4: Configuration Mode, Service Mode, and Alarm Active Function

1. From the service mode steady state, select menu item 5 by rotating the
knob until “5” appears in the SpO 2% display. Press the UPPER ALARM
LIMIT button. The ICC value appears as the two right-most digits in the
PULSE RATE display. The monitor’s configuration is represented by one
of the following values:

ICC
Value Monitor Configuration
03 SpO 2 only, with serial port
07 SpO 2 and ECG only, with serial port
0F SpO 2, ECG and respiration, with serial port
12 SpO 2 only, with wired network interface
16 SpO 2 and ECG only, with wired network interface
1E SpO 2, ECG and respiration, with wired network interface
FF Invalid configuration

If the displayed ICC value differs from the value stored in the EEPROM,
then the displayed value will flash.

2. If the displayed value is flashing, press the UPPER ALARM LIMIT

button to save the value as the default.

3. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.6 Menu Item 6: Total Operating Hours Report

This report displays the total number of operating hours logged by the unit
since it was produced.

1. From the service mode steady state, select menu item 6 by rotating the
knob until “6” appears in the SpO 2% display. Press the UPPER ALARM
LIMIT button. The total number of operating hours is displayed in the
SpO 2% and PULSE RATE displays. Possible values are from 0 to
999,999 hours.

2. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.7 Menu Items 7-16: Error Log Record Report

This report provides information regarding the last ten error codes recorded
by the monitor, the number of occurrences of that particular error, and the
number of operating hours at the last time the error occurred. The error log
has ten entries (menu items 7-16), as indicated below. Refer to Section 5,
Troubleshooting, and the Appendix for an explanation of error codes.

The following procedure is for Error Log Record 1 (menu item 7). Use the
same procedure to access Error Log Records 2 through 10 (menu items 8
through 16).

1. From the service mode steady state, select menu item 7 by rotating the
knob until “7” appears in the SpO 2% display. Press the UPPER ALARM
LIMIT button. The number “7.0” appears in the SpO 2% display.

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 Section 4: Configuration Mode, Service Mode, and Alarm Active Function

2. Read the error code in the PULSE RATE display. A value of “000”
indicates that the menu item contains no error code. If dashes are
displayed, the error log contents cannot be determined.

3. Rotate the control knob CW to display “7.1” in the SpO 2% display.

4. Read the number of occurrences of this particular error code in the

PULSE RATE display. If “256” is displayed, there have been 256 or more
occurrences.

5. Continue to rotate the control knob CW. The total number of operating
hours when the last instance of the error occurred is displayed in the
SpO 2% and PULSE RATE displays.

6. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.8 Menu Item 17: Instrument Identification (IID) Report

This report displays a hexadecimal number corresponding to the instrument

identifier. This number should agree with the address label on the outside of
the instrument. However, the label and the internal value may disagree if the
monitor UIF module was replaced and the external label was not changed.

1. From the service mode steady state, select menu item 17 by rotating the
knob until “17” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button. A hexadecimal number appears across the entire monitor
display, with an “H” in the last (far right) position.

2. Verify that this number agrees with the number on the monitor external
label. If the number does not agree, the number on the external label
should be changed to agree with the displayed number.

3. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.9 Menu Item 18: Power Status

This test allows you to determine battery conditions.

1. From the service mode steady state, select menu item 18 by rotating the
knob until “18” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button. The number “18.0” appears in the SpO2 % display. The
number shown in the PULSE RATE display is the lead-acid battery
voltage to the nearest tenth of a volt.

2. Rotate the control knob CW until “18.1” appears in the SpO2 % display.
The number shown in the PULSE RATE display is the charge bus
voltage to the nearest tenth of a volt.

3. Rotate the control knob CW until “18.2” appears in the SpO2 % display.
The number shown in the PULSE RATE display is the backup lithium
battery voltage to the nearest tenth of a volt.

Note: The control knob can be rotated until “18.3” appears in the
SpO 2% display. However, the number shown in the PULSE
RATE display has no meaning and can be ignored.

4. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

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Section 4: Configuration Mode, Service Mode, and Alarm Active Function

4.3.10 Menu Item 19: Persistent Time Sense Report

This report allows you to determine if the internal persistent time circuit is
keeping time correctly.

1. From the service mode steady state, select menu item 19 by rotating the
knob until “19” appears in the SpO2 % display.

2. Press the UPPER ALARM LIMIT button. The persistent time in seconds
is displayed in the SpO2% and PULSE RATE displays. For example, “001
688” indicates that the monitor has been powered on for 1,688 seconds =
28 minutes, 8 seconds. Make a note of the displayed time.

If the display reads “999 999” this indicates that persistent time is
greater than or equal to 999,999 seconds. If dashes are displayed, the
contents of the memory of the persistent time circuit are lost. This can
occur when the backup lithium battery has been replaced.

3. Using a watch or other timepiece, wait 3 minutes. Subtract the first

figure you noted from the figure now displayed on the N-3000. The
difference should equal approximately 3 minutes (180 seconds).

4. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.11 Menu Item 20: Reset to Factory Defaults

This function allows you to reset the monitor to the Nellcor Puritan Bennett
factory default settings (see the Specifications section of this manual).

From the service mode steady state, select menu item 20. As soon as you
press the UPPER ALARM LIMIT button, the default settings are reset. Any
preset configurable alarms are now lost. When the default settings are reset,
the monitor will beep three times and automatically return to the service
mode steady state. If the reset was not successful, an error code will be
displayed.

4.3.12 Menu Item 21: Initial Cluster Instrument Number Report

This report displays a hexadecimal number corresponding to the initial

internal stack address when the instrument is being used in a stack
configuration with an address conflict. Such a conflict may occur when
identical instrument types (for example, two N-3100s) are in the same stack.

1. From the service mode steady state, select menu item 21 by rotating the
knob until “21” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button. The two left-most digits in the PULSE RATE display are
the hexadecimal representation of the cluster instrument number. “H”
(for hexadecimal) is displayed as the right-most digit of the PULSE
RATE display.

2. If the displayed value is different than the EEPROM value, the display
will flash. Rotate the knob to adjust the cluster instrument number to
the desired value.

3. Press the UPPER ALARM LIMIT button to accept the displayed value as
the default value. The display stops flashing.

4. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

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4.3.13 Menu Item 22: Enable/Disable Latching Alarms

This function allows you to disable or enable the latching alarm feature. The
Nellcor Puritan Bennett factory default setting is latching alarm disabled.

1. From the service mode steady state, select menu item 22 by rotating the
knob until “22” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button.

2. Observe the enable/disable latching alarm setting of “OFF” or “ON” in

the PULSE RATE display.

OFF = latching alarm disabled

ON = latching alarm enabled

3. To change the enable/disable latching alarm setting, rotate the knob

until the desired setting is displayed (flashing).

4. Press the UPPER ALARM LIMIT button to store the default setting.

5. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.14 Menu Item 23: Enable/Disable Alarm Silence Reminder

This function allows you to disable or enable the alarm silence reminder
feature. The Nellcor Puritan Bennett factory default setting is alarm silence
reminder enabled.

1. From the service mode steady state, select menu item 23 by rotating the
knob until “23” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button.

2. Observe the alarm silence reminder setting of “OFF” or “ON” in the

PULSE RATE display.

OFF = alarm silence reminder disabled

ON = alarm silence reminder enabled

3. To change the alarm silence reminder setting, rotate the knob until the
desired setting is displayed (flashing).

4. Press the UPPER ALARM LIMIT button to store the default setting.

5. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.15 Menu Item 25: Dump EEPROM Data

This function allows you to dump the entire contents of the EEPROM to a
serial data capture device. This data may then be transmitted to Nellcor
Puritan Bennett to assist in diagnosing the condition of the instrument.

Note: The N-3000 must be operating from AC power to perform this menu
item.

1. Turn the N-3000 off.

2. Connect the N-3000 to a PC through the serial port.

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Section 4: Configuration Mode, Service Mode, and Alarm Active Function

3. Execute your communication software application. Port settings should

be set as indicated below:

Baud Rate 19,200 (or equivalent to N-3000 setting as

determined by using menu item 60)
Parity N
Data Bits 8
Stop Bits 1

4. Power-on the N-3000 and place it in the service mode steady state.

5. Select menu item 25 by rotating the knob until “25” appears in the
SpO 2% display. Press the UPPER ALARM LIMIT button. “EE” will be
displayed in the PULSE RATE display.

6. Press the PRINT button to transmit the contents of the EEPROM

memory out of the serial port.

7. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.16 Menu Item 28: Enable/Disable Battery Charge Circuit

This test allows you to turn the battery charging circuit on or off.

1. From the service mode steady state, select menu item 28 by rotating the
knob until “28” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button.

2. Observe the battery charging circuit setting of “OFF” or “ON” in the

PULSE RATE display.

OFF = battery charging circuit disabled

ON = battery charging circuit enabled

3. To enable or disable the battery charge circuit, rotate the knob until the
desired setting is displayed (flashing). Press the UPPER ALARM LIMIT
button.

4. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.17 Menu Item 29: Instrument Compatibility Report

This function allows you to determine the cause of an “instruments not

compatible” error message.

1. From the service mode steady state, select menu item 29 by rotating the
knob until “29” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button. The number “29.0” appears in the SpO2 % display. The
number in the PULSE RATE display is the sensorbus protocol version
and revision number of the N-3000.

2. Rotate the knob until “29.1” appears in the SpO 2% display. Press the
UPPER ALARM LIMIT button. The number in the PULSE RATE
display is the multicast version and revision number of the N-3000.

3. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4-16
 Section 4: Configuration Mode, Service Mode, and Alarm Active Function

4.3.18 Menu Item 30: SpO 2 RCAL Report

This function allows you to check the sensor RCAL value readings.

1. Connect the SRC-2 tester or a compatible sensor to the N-3000.

2. Select menu item 30 by rotating the knob until “30” appears in the
SpO 2% display. Press the UPPER ALARM LIMIT button.

3. Read the RCAL standard representation of the nominal sensor resistance

in the PULSE RATE display.

4. If connected to an SRC-2 tester, set the SRC-2 RCAL/Mode switch to 63.

The RCAL value “63” is displayed in the PULSE RATE display. Set the
SRC-2 RCAL/Mode switch to 64. The RCAL value “64” is displayed in the
PULSE RATE display.

5. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.19 Menu Item 31: SpO 2 IR and Red Offset Report

This function allows you to validate the operation of the SpO 2 module. The
values represent the DC voltage offset for the current amplifier gain when
the amplifier inputs are zeroed.

1. Connect the sensor cable and SRC-2 to the N-3000.

2. Set the SRC-2 as follows:

SWITCH POSITION

RATE 38
LIGHT LOW
MODULATION OFF
MODE LOC/RCAL 63

3. From the service mode steady state, select menu item 31 by rotating the
knob until “31” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button. The SpO2 IR offset appears in the SpO 2% display, and the
SpO 2 red offset appears in the PULSE RATE display. The values are
displayed in millivolts.

4. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.20 Menu Item 32: SpO 2 Corrected IR and Red Signals Report

This function allows you to validate the operation of the SpO 2 module. The
values represent the outputs of the IR and red sensor channels after the
amplifier offset values have been applied.

1. Connect the sensor to the N-3000.

2. Verify that the SpO2 module is set for automatic operation using menu
item 39 (paragraph 4.3.27).

3. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4-17
Section 4: Configuration Mode, Service Mode, and Alarm Active Function

4. From the service mode steady state, select menu item 32 by rotating the
knob until “32” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button. The SpO2 corrected IR output signal is displayed in the
SpO 2% display in hundredths of volts. The SpO 2 corrected red output
signal is displayed in the PULSE RATE display in hundredths of volts.

5. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.21 Menu Item 33: SpO 2 IR LED Drive Test

This function allows you to validate sensors and/or the operation of the SpO2
module.

1. Connect the sensor to the N-3000.

2. Verify that the SpO2 module is set for automatic operation using menu
item 39 (paragraph 4.3.27).

3. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4. From the service mode steady state, select menu item 33 by rotating the
knob until “33” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button.

5. The SpO2 IR drive value (between 0–255) is displayed in the PULSE

RATE display.

6. To adjust the drive value, rotate the Nellcor Puritan Bennett knob. The
PULSE RATE display will flash. Pressing the UPPER ALARM LIMIT
button will set the displayed value in the SpO 2 module, which will cease
its automatic operation. The PULSE RATE display will stop flashing.

7. Press and hold the PRINT button to display the SpO2 corrected IR and
red output signals as described in menu item 32. Release the PRINT
button.

8. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.22 Menu Item 34: SpO 2 Red LED Drive Test

This function allows you to validate sensors and/or the operation of the SpO2
module.

1. Connect the sensor to the N-3000.

2. Verify that the SpO2 module is set for automatic operation using menu
item 39 (paragraph 4.3.27).

3. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4. From the service mode steady state, select menu item 34 by rotating the
knob until “34” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button.

5. The SpO2 red LED drive value (between 0-255) is displayed in the
PULSE RATE display.

4-18
 Section 4: Configuration Mode, Service Mode, and Alarm Active Function

6. To adjust the drive value, rotate the knob. The PULSE RATE display
will flash. Pressing the UPPER ALARM LIMIT button will set the
displayed value in the SpO2 module, which will cease its automatic
operation. The PULSE RATE display will stop flashing.

7. Press and hold the PRINT button to display the SpO2 corrected IR and
red output signals as described in menu item 32. Release the PRINT
button.

8. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.23 Menu Item 35: SpO 2 DM-Gain Test

This function allows you to validate sensors and/or the operation of the SpO2
module.

1. Connect the sensor to the N-3000.

2. Verify that the SpO2 module is set for automatic operation using menu
item 39 (paragraph 4.3.27).

3. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4. From the service mode steady state, select menu item 35 by rotating the
knob until “35” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button.

5. The SpO2 demodulator gain value (from 0 to 6) is displayed in the

PULSE RATE display.

6. To adjust the gain, rotate the knob. The PULSE RATE display will flash.
Pressing the UPPER ALARM LIMIT button will set the displayed value
in the SpO 2 module, which will cease its automatic operation. The
PULSE RATE display will stop flashing.

7. Press and hold the PRINT button to display the SpO2 corrected IR and
red output signals as described in menu item 32. Release the PRINT
button.

8. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.24 Menu Item 36: SpO 2 P-Gain Test

This function allows you to validate sensors and/or the operation of the SpO2
module.

1. Connect the sensor to the N-3000.

2. Verify that the SpO2 module is set for automatic operation using menu
item 39 (paragraph 4.3.27).

3. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4. From the service mode steady state, select menu item 36 by rotating the
knob until “36” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button.

4-19
Section 4: Configuration Mode, Service Mode, and Alarm Active Function

5. The SpO2 preamp gain (from 0 to 3) is displayed in the PULSE RATE

display.

6. To adjust the gain value, rotate the knob. The PULSE RATE display will
flash. Pressing the UPPER ALARM LIMIT button will set the displayed
value in the SpO 2 module, which will cease its automatic operation. The
PULSE RATE display will stop flashing.

7. Press and hold the PRINT button to display the SpO2 corrected IR and
red output signals as described in menu item 32. Release the PRINT
button.

8. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.25 Menu Item 37: Set SpO2 Analog Test Mode

This function allows you to validate sensors and/or the operation of the SpO2
module.

1. Connect the sensor to the N-3000.

2. From the service mode steady state, select menu item 37 by rotating the
knob until “37” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button.

3. The test mode setting of “0” (normal operation) is displayed in the

PULSE RATE display. “SEr” is displayed in the AUXILIARY display and
“37” is displayed in the SpO 2% digital display.

4. Rotate the knob to select other settings.

1 = “zero” setting
2 = “system test” setting

If the displayed value is different from the current SpO2 value, the
display will flash.

Pressing the UPPER ALARM LIMIT button will set the displayed value
in the SpO 2 module, which will cease its automatic operation.

5. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.26 Menu Item 38: SpO 2 A/D-Cal Line Test

This function allows you to verify calibration of the SpO2 A/D converter.

1. From the service mode steady state, select menu item 38 by rotating the
knob until “38” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button.

4-20
 Section 4: Configuration Mode, Service Mode, and Alarm Active Function

2. Observe the PULSE RATE display. The possible values 0, 1, 2, or 3

indicate the following status

“0” Indicates that both A/D converters are undergoing self-calibration,

which will take approximately 3 seconds. A value of “0” after the
3-second period indicates that both converters have failed self-
calibration.

“1” Indicates that the IR A/D converter has completed self-calibration

and the red A/D is still undergoing self-calibration or has failed
self-calibration.

“2” Indicates that the red A/D converter has completed self-calibration
and the IR A/D is still undergoing self-calibration or has failed self-
calibration.

“3” Indicates that both converters have completed self-calibration.

3. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.27 Menu Item 39: SpO 2 Enable Automatic Operation

This function allows you to reset and confirm that the SpO2 module is
operating in the automatic mode.

1. Connect the sensor to the N-3000.

2. From the service mode steady state, select menu item 39 by rotating the
knob until “39” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button.

3. Observe the SpO2 automatic operation setting of “OFF” or “ON” in the

PULSE RATE display.

OFF = SpO 2 module is not in automatic operation

ON = SpO2 module is in automatic operation

4. Rotate the knob to change the display and turn automatic operation ON
or OFF.

5. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.28 Menu Item 60: Set Serial Port Baud Rate

This function allows you to set the default serial port baud rate.

1. From the service mode steady state, select menu item 60 by rotating the
knob until “60” appears in the SpO2 % display. Press the UPPER ALARM
LIMIT button.

2. The current baud rate, in hundreds, is displayed in the PULSE RATE

display. To change the default baud rate setting, rotate the knob until
the desired setting is displayed.

Note: When connected to a PC in the RS-232 format, a baud rate above

19,200 should not be used.

3. Press the UPPER ALARM LIMIT button to store the default setting.

4-21
Section 4: Configuration Mode, Service Mode, and Alarm Active Function

4. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.29 Menu Item 61: Serial Port Loop Back Test

This test verifies that, when the N-3000 is connected to a PC through the
N-3000 serial port, the serial port receive hardware is functional.

Note: The N-3000 must be operating from AC power to perform this menu
item.

1. Turn the N-3000 off.

2. Connect the N-3000 to a PC through the serial port.

3. Execute your communication software application. Port settings should

be set as indicated below:

Baud Rate 19200 (or as set using menu item 60)

Parity N
Data Bits 8
Stop Bits 1

4. Turn on the N-3000 and place it in the service mode.

5. Select menu item 61 by rotating the knob until “61” appears in the
SpO 2% display. Press the UPPER ALARM LIMIT button.

6. Type any characters on your PC keyboard and verify that the characters
are echoed on the PC screen. This confirms that data received on the
serial port receive line is transmitted on the transmit data line.

7. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

4.3.30 Menu Item 62: Serial Port Transmit Test

This test verifies that, when the N-3000 is connected to a PC through the
N-3000 serial port, the serial port transmit hardware is functional.

Note: The N-3000 must be operating from AC power to perform this menu
item.

1. Perform steps 1 through 4 as indicated in paragraph 4.3.29, menu item

61.

2. Select menu item 62 by rotating the knob until “62” appears in the
SpO 2% display. Press the UPPER ALARM LIMIT button.

3. Verify that a fixed pattern of bytes (0 through 255) is repeatedly sent on

the transmit data line. The characters are repeatedly sent on the
transmit data line when menu item 62 is selected.

4. Press the LOWER ALARM LIMIT button to return to the service mode
steady state.

Caution: Menu items 70 and above are for factory purposes only.
Adjustment of menu items 70 and above by other than qualified
factory personnel may cause the N-3000 to malfunction.

4-22
 Section 4: Configuration Mode, Service Mode, and Alarm Active Function

4.4 ALARM ACTIVE FUNCTION

The N -3000 alarm active function allows low, medium, or high priority
alarms to be monitored from a remote location via the N-3000 serial port.
Alarm monitoring also applies to an attached, active N-3100. This function is
automatically enabled during the power-on cycle.

Pin 6 is open when no alarms are active. Alarm activity results in pin 6
shorting to ground. The pin will remain shorted to ground as long as the
alarm is sounding.

1 2
3 4
5 6

Figure 4-1: Serial Port Pin Locations

If voltage levels of ±7 volts on pin 1 are desired for remote alarm monitoring
(while in RS-232 mode), short together the DSR (pin 2) and TXD (pin 3) lines
of the communication cable. Once the alarm active function has been enabled
during power-on, an alarm will toggle the DTR line pin 1 from a logic LOW of
-7 volts to a HIGH of +7 volts. As long as the alarm is sounding, this line will
remain HIGH. When the alarm is silenced, or becomes inactive, the line will
return to its LOW logic level.

If a continuous 3.3 volt signal on pin 6 is desired (as when using the Nellcor
Puritan Bennett SOC-3 adapter), change the dip switch settings on the
Communications PCB as instructed in paragraph 6.5.1.

4-23
SECTION 5: TROUBLESHOOTING
5.1 Introduction
5.2 How to Use this Section
5.3 Who Should Perform Repairs
5.4 Replacement Level Supported
5.5 Obtaining Replacement Parts
5.6 Troubleshooting Guide

5.1 INTRODUCTION

This section explains how to troubleshoot the N-3000 if problems arise.

Tables are supplied that list possible monitor difficulties, along with probable
causes, and recommended actions to correct the difficulty.

5.2 HOW TO USE THIS SECTION

Use this section in conjunction with Section 3, Performance Verification, and

Section 7, Spare Parts. To remove and replace a part you suspect is defective,
follow the instructions in Section 6, Disassembly Guide. The circuit analysis
section in the Technical Supplement offers information on how the monitor
functions.

5.3 WHO SHOULD PERFORM REPAIRS

Only qualified service personnel should open the monitor housing, remove
and replace components, or make adjustments. If your medical facility does
not have qualified service personnel, contact Nellcor Puritan Bennett
Technical Services or your local Nellcor Puritan Bennett representative.

5.4 REPLACEMENT LEVEL SUPPORTED

The replacement level supported for this product is to the printed circuit
board (PCB) and major subassembly level. Once you isolate a suspected PCB,
follow the procedures in Section 6, Disassembly Guide, to replace the PCB
with a known good PCB. Check to see if the trouble symptom disappears and
that the monitor passes all performance tests. If the trouble symptom
persists, swap back the replacement PCB with the suspected malfunctioning
PCB (the original PCB that was installed when you started troubleshooting)
and continue troubleshooting as directed in this section.

5.5 OBTAINING REPLACEMENT PARTS

Nellcor Puritan Bennett Technical Services provides technical assistance

information and replacement parts. To obtain replacement parts, contact
Nellcor Puritan Bennett or your local Nellcor Puritan Bennett representative.
Refer to parts by the part names and part numbers listed in Section 7, Spare
Parts.

5-1
Section 5: Troubleshooting

5.6 TROUBLESHOOTING GUIDE

Problems with the N-3000 are separated into the categories indicated in
Table 5-1. Refer to the paragraph indicated for further troubleshooting
instructions.

Note: Taking the recommended actions discussed in this section will correct
the majority of problems you will encounter. However, problems not
covered here can be resolved by calling Nellcor Puritan Bennett
Technical Services or your local Nellcor Puritan Bennett
representative.

Table 5-1: Problem Categories

Problem Area Refer to Paragraph

1. Power 5.6.1

• No power-up on AC and/or DC

• Fails power-on self-test

• Powers down without apparent

cause

2. Error Messages 5.6.2

3. Buttons/Knob 5.6.3

• Monitor does not respond properly to

buttons and/or knob

4. Display/Alarms 5.6.4

• Displays do not respond properly

• Alarms or other tones do not sound

properly or are generated without
apparent cause

5. Operational Performance 5.6.5

• Displays appear to be operational,

but monitor shows no readings

• Suspect readings

6. Stacked Configuration 5.6.6

• N-3000 operates properly when used

alone but not when stacked

7. Serial Port 5.6.7

• N-3000 and PC not communicating

properly

All of the categories in Table 5-1 are discussed in the following paragraphs.

5-2
 Section 5: Troubleshooting

5.6.1 Power

Power problems are related to AC and/or DC. Table 5-2 lists recommended
actions to power problems.

Table 5-2: Power Problems

Condition Recommended Action

1. BATTERY-IN- 1. Ensure that the SPS power supply is plugged into

USE/BATTERY an operational AC outlet. If it is, and the green
LOW indicator indicator light is not lit, replace the power supply.
lights steadily
while N-3000 is 2. If the green SPS indicator is lit, ensure that the
connected to AC power supply is properly plugged into the N-3000.
via the external
power supply. 3. Check the fuse. The fuse is located on the lower
docking connector as indicated in paragraph 6.3
and Figure 6-3 of the Disassembly Guide section.
Replace if necessary.

4. Check the ribbon connection from the bottom

enclosure to the UIF PCB, as instructed in
paragraph 6.5 of the Disassembly Guide section. If
the connection is good, replace the UIF PCB.

2. The N-3000 does 1. The battery may be discharged. To recharge the

not operate when battery, refer to paragraph 3.3.2, Battery Charge.
disconnected The monitor may be used with a less than fully
from its external charged battery but with a corresponding decrease
power supply or in operating time from that charge.
the power failure
alarm sounds 2. If the battery fails to hold a charge, replace the
when AC power battery as indicated in Section 6, Disassembly
is disconnected. Guide.

3. BATTERY-IN- There are 15 minutes or less of usable charge left

USE/BATTERY on the N -3000 battery. At this point, if possible,
LOW indicator cease use of the N-3000 on battery power, connect it
flashes during to its external power source and allow it to recharge
DC operation. (approximately 14 hours). The N-3000 may
continue to be used while it is recharging.

4. The microproces- Replace the UIF PCB.

sor failure alarm
sounds and no
error code is
displayed.

5-3
Section 5: Troubleshooting

5.6.2 Error Codes

When there is a problem within the N-3000 monitor, an error code may be
displayed on the front panel, as illustrated:

SpO2 % / min

These codes correspond to messages that indicate what part of the monitor is
at fault. Actions to take when encountering error codes are listed below. For a
more thorough understanding of the error codes, refer to Appendix A.

5.6.2.1 User-Correctable Error Codes

The following error codes can be corrected by the operator:

Error Code Explanation

055 Current user input values (limits, volumes, times) have been
lost during an internal reset and the unit has returned to
power-on defaults. Reset to desired values if different from
power-on defaults.
058 Alarm and beep volume, audible alarm silence duration and
operating mode have returned to power-on defaults due to an
internal instrument reset.
081 Cannot calibrate sensor (possible shorted/open LED or cable).
Check sensor and cable connections. Check sensor and cable;
replace if necessary. If replacing sensor and/or cable does not
fix the problem, remove the N-3000 monitor from service. Use
the SpO 2 diagnostic tests (service mode menu item numbers 31
through 39) to further evaluate the problem.

5.6.2.2 Failure Error Codes

Failure error codes are those that are displayed by the monitor with a leading
digit other than “0”. In some cases, these codes can be cleared by simply
turning the monitor off and then on again.

Table 5-3 lists the possible failure error codes and the recommended action to
take. If the action requires replacement of a PCB, refer to Section 6,
Disassembly Guide . If the recommended action fails to solve the problem,
notify Nellcor Puritan Bennett Technical Services or your local Nellcor
Puritan Bennett representative. Refer to the Appendix for a further
explanation of the codes.

5-4
 Section 5: Troubleshooting

Table 5-3: N-3000 Failure Error Codes

Error Code Recommended Action

106 1. Turn the monitor off, then on again.
2. If the error code still appears, power-down the
monitor and verify that the UIF PCB ROM (U3) is
securely seated in its socket. Turn the monitor on
again.
3. If the error code still appears, power down the
monitor and replace the UIF PCB.
108, 109, 111, 178 1. Turn the monitor off, then on again.
2. If the error code still appears, power-down the
monitor and replace the UIF PCB.
110 1. Turn the monitor off, then on again.
2. Use service mode menu item number 18 to evaluate
the status of the lithium backup battery.
3. If necessary, power-down the monitor and replace the
lithium backup battery.
4. If the error code still appears, power down the
monitor and replace the UIF PCB.
151, 175, 176 1. Turn the monitor off, then on again.
2. If the error code still appears, power-down the
monitor and verify that the SpO 2 Module ROM is
securely seated in the socket.
3. Verify that the SpO2 Controller PCB is securely
seated.
4. Turn the monitor on. If the error code still appears,
replace the SpO 2 Controller PCB.
5. If the error code still appears, power-down the
monitor and replace the UIF PCB.
159 1. Use the service mode menu item 20 to reset the
default values to factory default values as discussed
in Section 4, Configuration and Service Modes.
2. If the error code still appears, power-down the
monitor and replace the UIF PCB.
3. If the error code still appears, power down the
monitor and replace the SpO2 Controller PCB.
177 1. Turn the monitor off, then on again.
2. If the error code still appears and the N-3000 is
stacked with another instrument, turn all stacked
instruments off and then on again.

5-5
Section 5: Troubleshooting

Table 5-3: N-3000 Failure Error Codes - Continued

Error Code Recommended Action

178, 191 1. Turn the monitor off, then on again.
2. If the error code still appears, use the service mode,
menu item 20, to reset the default values to factory
default values as discussed in Section 4, Configuration
and Service Modes.
3. If the error code still appears, power-down the monitor
and replace the UIF PCB.
179 1. Turn the monitor off, then on again.
2. If the error code still appears, verify compatibility of
UIF Module SW ROM and SpO 2 Module SW ROM part
numbers by using service mode menu item 17.
3. If the numbers are compatible, power-down and verify
that the SpO 2 Module ROM is securely seated.
4. Verify that the SpO2 Controller PCB and SpO2 module
are securely seated.
5. Turn the monitor on. If the error code still appears,
replace the SpO 2 Controller PCB.
6. If the error code still appears, power-down the monitor
and replace the UIF PCB.
183, 283 Turn the monitor off, then on again.
189 1. Turn the monitor off, then on again.
2. If the error code still appears, power-down the monitor
and replace the UIF PCB.
192, 195, 196 1. Turn the monitor off, then on again.
2. Use the service mode, menu item 29, to verify the
compatibility of your software.
3. If the error code still appears, verify compatibility of the
ROMs by calling Nellcor Puritan Bennett Technical
Services or your local Nellcor Puritan Bennett
representative.
203, 206, 211 1. Turn the monitor off, then on again.
2. If the error code still appears, power-down the monitor
and replace the SpO 2 Controller PCB.
204, 205 1. Turn the monitor off, then on again.
2. If the error code still appears, power-down the monitor
and replace the SpO 2 PCB.
3. If the error code still appears, power down the monitor
and replace the SpO 2 Controller PCB.
275, 276 1. Turn the monitor off, then on again.
2. If the error code still appears, power-down and verify
that the SpO 2 Controller PCB is securely seated.
3. If the error code still appears, replace the SpO 2
Controller PCB.
4. If the error code still appears, power down the monitor
and replace the UIF PCB.

5-6
 Section 5: Troubleshooting

5.6.3 Buttons/Knob

Table 5-4 lists symptoms of problems relating to nonresponsive buttons or the

Nellcor Puritan Bennett knob and recommended actions. If the action
requires replacement of a PCB, refer to Section 6, Disassembly Guide .

Table 5-4: Buttons/Knob Problems

Condition Recommended Action

1. The N -3000 turns on 1. If possible, verify the problem with the service
but does not respond mode, menu item 2, knob and lamp test.
to the knob (buttons
are operational). 2. Verify proper connection between knob and
UIF PCB.

3. If the condition still persists, replace the UIF

PCB.

2. The N -3000 responds 1. Verify the problem and identify faulty buttons
to some, but not all with the service mode, menu item 3, button
buttons. test.

2. If faulty buttons are AUDIBLE ALARM

SILENCE button or NEW PATIENT/
NEONATAL button, replace UIF PCB.

3. If faulty buttons are on front panel, replace

Display PCB. If the buttons still do not work,
replace the UIF PCB.

3. The N-3000 turns on 1. Press the NEW PATIENT/NEONATAL button

but does not respond twice rapidly. If the NEONATAL MODE
to either the knob or indicator lights, replace the Display PCB.
any of the buttons.
2. If the NEONATAL MODE indicator does not
light, replace the UIF PCB.

5-7
Section 5: Troubleshooting

5.6.4 Display/Alarms

Table 5-5 lists symptoms of problems relating to nonfunctioning displays,

audible tones or alarms, and recommended actions. If the action requires
replacement of a PCB or module, refer to Section 6, Disassembly Guide.

Table 5-5: Display/Alarms Problems

Condition Recommended Action

1. Display values are 1. If the sensor is connected, replace the sensor

missing or erratic. connector assembly.

2. If the condition persists, replace the sensor

extension cable.

3. If the condition does not change, replace the

SpO 2 PCB.

4. If the condition still persists, replace the UIF

PCB.

2. Display segments do 1. Verify the problem with the service mode

not light. menu item 2, knob and lamp test.

2. Check the connection between the UIF PCB

and the Display PCB.

3. If the condition does not change, replace the

Display PCB.

4. If the condition still persists, replace the UIF

PCB.

3. Alarm sounds for no 1. Moisture or spilled liquids can cause an alarm

apparent reason. to sound. Allow the monitor to dry thoroughly
before using.

2. If the condition persists, replace the UIF PCB.

4. Alarm does not sound. 1. Verify the problem with the service mode
menu item 4, speaker test.

2. Replace the speaker as described in Section 6,

Disassembly Guide .

3. If the condition persists, replace the UIF PCB.

5-8
 Section 5: Troubleshooting

5.6.5 Operational Performance

Table 5-6 lists symptoms of problems relating to operational performance (no

error codes displayed) and recommended actions. If the action requires
replacement of a PCB or module, refer to Section 6, Disassembly Guide.

Table 5-6: Operational Performance Problems

Condition Recommended Action

1. The PULSE 1. The sensor may be damaged; replace it.

AMPLITUDE
indicator seems to 2. If the condition still persists, replace the UIF
indicate a pulse, but PCB.
the digital displays
show zeroes.

2. SpO 2 or pulse rate 1. The sensor may be damp or may have been
values change rapidly; reused too many times. Replace it.
PULSE AMPLITUDE
indicator is erratic. 2. An electrosurgical unit (ESU) may be
interfering with performance:

– Move the N-3000 and its cables and sensors as

far from the ESU as possible.

– Plug the N-3000 power supply and the ESU

into different AC circuits.

– Move the ESU ground pad as close to the

surgical site as possible and as far away from
the sensor as possible.

3. Verify the SpO 2 performance with service

mode menu items 31-39. Verify the pulse
measurement function with the SRC-2.

4. If the condition still persists, replace the UIF

PCB.

5-9
Section 5: Troubleshooting

5.6.6 Stacked Operation

Table 5-7 lists symptoms of problems encountered while in the stacked

configuration with the N-3100 and recommended actions. Refer to the N-3100
service manual for more troubleshooting information.

Table 5-7: Stack Problems

Condition Recommended Action

1. BATTERY IN USE/ 1. Ensure that the power supply is

BATTERY LOW indicators on plugged into an operational AC outlet.
the N-3000 and N-3100 light If it is, and the green indicator light is
steadily while they are not lit, replace the power supply.
connected to AC via the
external power supply. Both 2. If the green SPS indicator is lit,
units are operational. ensure that the power supply is
properly plugged into the N-3100.

3. Check the N-3000 fuse and replace if

necessary.

2. BATTERY IN USE/ 1. Ensure that a good docking connection

BATTERY LOW indicator on exists between the N-3000 and
the N-3000 lights steadily but N-3100.
N-3100 does not while they
are connected to AC. The 2. Check the N-3000 fuse and replace it if
units are operational. necessary, as indicated in the
Disassembly Guide section.

3. BATTERY IN Check the N-3100 fuses and replace if

USE/BATTERY LOW necessary, as indicated in the
indicators on the N-3100 light Disassembly Guide section of the
steadily but N-3000 does not N-3100 service manual.
while they are connected to
AC via the external power
supply. Both units are
operational.

4. The N-3000 and N-3100 do 1. The N -3000 battery may be

not operate when discharged. To recharge the battery,
disconnected from the keep the N-3000 connected to its
external power supply. external power supply. Confirm that
the BATTERY CHARGING indicator
lights. The monitors may be used with
a less than fully charged battery but
with a corresponding decrease in
operating time from that charge.

2. If the battery fails to hold a charge,

replace as indicated in the
Disassembly Guide section.

5-10
 Section 5: Troubleshooting

Table 5-7: Stack Problems - Continued

Condition Recommended Action

5. While operating on 1. Ensure that a good docking connection

battery power, the exists between the N-3000 and N-3100.
N-3000 operates with
BATTERY IN 2. If the condition persists, recharge the
USE/BATTERY LOW battery. (The battery may have enough
indicator lighting power left to operate the N-3000 but not the
steadily but N-3100 does N-3100.)
not operate.

5.6.7 Serial Port

Table 5-8 lists symptoms of problems relating to the serial port and
recommended actions. If the action requires replacement of a PCB or module,
refer to Section 6, Disassembly Guide.

Table 5-8: Serial Port Problems

Condition Recommended Action

1. The measured voltages 1. Ensure the Communications PCB switch

at the serial port settings are as described in paragraph
(paragraph 3.3.5.3) are 6.5.1.
incorrect.
2. If the condition persists, replace the
Communications PCB.

3. If the condition still persists, replace the

UIF PCB.

2. The measured voltages 1. Perform the serial port loop back (menu
at the serial port item 61) and serial port transmit (menu
(paragraph 3.3.5.3) are item 62) tests in the service mode
correct but messages are (paragraphs 4.3.29 and 4.3.30). If the tests
not being transmitted or are successful, recheck the message formats
received. you are sending to the monitor, ensure that
a good cable connection exists between PC
and N-3000, and verify the baud rate using
the service mode, menu item 60. (When
connected to a PC in the RS-232 format, a
baud rate above 19,200 should not be used.)

2. If the test fails, ensure the Communications

PCB switch settings are as described in
paragraph 6.5.1.

3. If the condition persists, replace the

Communication PCB.

4. If the condition still persists, replace the

UIF PCB.

5-11
SECTION 6: DISASSEMBLY GUIDE
6.1 Introduction
6.2 Removing the Battery
6.3 Battery Replacement
6.4 Fuse Replacement
6.5 Monitor Disassembly
6.6 Removing the Alarm Speaker
6.7 Removing the SpO2 PCB and SpO2 Controller PCB
6.8 Removing the Communications PCB
6.9 Removing the UIF and Display PCB
6.10 Control Knob Assembly Replacement
6.11 Lithium Battery Replacement
6.12 Reassembly

6.1 INTRODUCTION

The N-3000 can be disassembled down to all major component parts,

including:

• PCBs
• batteries
• cables
• function buttons
• chassis enclosures

The following tools are required:

• small, Phillips-head screwdriver

• medium, Phillips-head screwdriver
• needle-nose pliers or 1/4-inch socket
• 7/16-inch socket
• 7/16-inch torque wrench, 10 inch-pounds, required only when replacing
knob

WARNING: Before attempting to open or disassemble the N-3000,

disconnect the power cord from the N-3000.

Caution: Observe ESD (electrostatic discharge) precautions when

working within the unit.

Caution: Remove the battery before disassembling the unit.

Note: Some spare parts have a business reply card attached. When you
receive these spare parts, please fill out and return the card.

6.2 REMOVING THE BATTERY

Caution: If it is necessary to apply AC power while the battery cover

is removed, do not connect the SPS power supply to the monitor
while the power supply is plugged into AC power. Instead, first
connect the power supply to the monitor, then connect the power
supply to AC power. Misalignment of the power supply cord
connector with the lower docking connector may result in damage to
the monitor. (This caution does not apply when the battery cover is
attached to the N-3000.)

6-1
Section 6: Disassembly Guide

Perform the following steps to replace the battery.

1. Turn the N-3000 OFF by pressing the ON/STANDBY button.

2. Disconnect the monitor from the SPS power supply.

3. Set the N-3000 upside down facing you, as shown in Figure 6-1.

Battery cover

Squeeze
Battery cover
fasteners

NE
Squeeze
LLC
OR
Sym
pho
ny
N-3
000

Figure 6-1: Battery Replacement

4. Loosen the two battery cover retaining fasteners securing the battery
compartment cover.

5. Gently squeeze the battery cover sides in the middle as you swing the
cover open (it is hinged on the right with three tabs that extend into slots
on the chassis).

6. Lift the battery out of the battery bracket, as shown in Figure 6-2. It may
be necessary to use the edge of a flat tip screwdriver to gently pry the
battery loose.

6-2
 Section 6: Disassembly Guide

Battery cover

Battery

Power
connector

NE
LLC
OR
Sym
pho
ny
N-3
000

Battery bracket

Figure 6-2: Removing the Battery

7. Disconnect the power connector from the battery.

6.3 BATTERY REPLACEMENT

1. Complete the procedure in paragraph 6.2.

2. The lead-acid battery is recyclable. Do not dispose of battery by placing it

in the regular trash. Dispose of properly or return to Nellcor Puritan
Bennett Technical Services for disposal.

3. Connect the power connector to the new battery. The connector can only
be mated one way.

4. Position the battery into the battery bracket.

5. Replace the battery cover and tighten the retaining fasteners.

6. Turn the monitor on and verify proper operation.

Note: If the replacement battery is low on charge, the BATTERY

CHARGING indicator may not light if the monitor is off and
connected to AC power. If that is the case, turn the N-3000 on to
begin charging.

6-3
Section 6: Disassembly Guide

6.4 FUSE REPLACEMENT

1. Complete the procedure in paragraph 6.2.

2. Replace the fuses as shown in Figure 6-3 with an equivalent

replacement.

Fuse F2, 2.5 amp Fuse F1, 1 amp

Battery

Figure 6-3: N-3000 Fuses

3. Reinstall the battery and battery cover.

Caution: The battery fuse (F2) on the Docking Connector PCB must
be removed before disconnecting the docking connector cable from
connector J17 as indicated in paragraph 6.5. Failure to remove the
fuse may result in damage to the Lower Docking Connector PCB or
UIF PCB.

6.5 MONITOR DISASSEMBLY

1. Complete the procedure in paragraph 6.2.

2. Remove the four corner screws that hold the monitor together (Figure 6-4).

Screws Screws

Figure 6-4: N-3000 Corner Screws

6-4
 Section 6: Disassembly Guide

3. Pull the carrying handle down to the right.

4. Pull the unit apart, swinging the bottom half to your left, as illustrated
in Figure 6-5.

Connector J13

Docking connector
cable

NE
LLC
OR
Sym
pho
ny
N-3
000

Bottom enclosure

Figure 6-5: Opening the N-3000 Monitor

Caution: The battery fuse (F2) on the Docking Connector PCB must
be removed as indicated in paragraph 6.4 before disconnecting the
docking connector cable from connector J17. Failure to remove the
fuse may result in damage to the Lower Docking Connector PCB or
UIF PCB.

5. The docking connector cable is plugged into connector J13 on the UIF
PCB. Disconnect the docking connector cable from connector J13 by
gently pushing the top of the connector down, while pulling straight up
on the cable.

6.5.1 Communications Board Switch Settings

1. To change the switch settings on your communications PCB, complete

steps 1 through 4 in paragraph 6.5.

2. The switch settings on the Communication PCB are shipped for RS-232
communications and should be as follows (refer to Figure 6-5):

SW1 - Positions 1, 3, 5, and 7 = ON; Positions 2, 4, and 6 = OFF

SW2 - Positions 2, 4, and 6 = ON; Positions 1, 3, 5, and 7 = OFF
SW3 - Position 1 = ON; Position 2, 3, and 4 = OFF
Jumper J6 in “IGND” position.

6-5
Section 6: Disassembly Guide

If a continuous 3.3 volt signal at pin 6 of the serial port (Figure 3.3) is
required (as when using the Nellcor Puritan Bennett SOC-3 adapter),
change the SW3 settings as follows:

SW3 - Position 1 = OFF; Position 2, 3, and 4 = ON

If RS-422 settings are required, change SW1 and SW2 as follows:

SW1 - Positions 1, 3, 5, and 7 = OFF; Positions 2, 4, and 6 = ON

SW2 - Positions 2, 4, and 6 = OFF; Positions 1, 3, 5, and 7 = ON
SW3 - Position 1 = ON; Position 2, 3, and 4 = OFF

6.6 REMOVING THE ALARM SPEAKER

1. Complete the procedure in paragraph 6.5.

2. Remove the handle and spring assembly on the right side of the unit, as
illustrated in Figure 6-6, lifting it up out of the molded chassis cradle.

Handle
Spring

Left side panel

Alarm speaker

Speaker gasket

Piezo power loss

alarm speaker

Connector J2

NE
LLC
OR
Sym
pho
ny
N-3
000

Figure 6-6: Handle, Left Side Panel, and Speaker Disassembly

3. Remove the left side panel (this is on your right, as illustrated above) by
pulling straight up; be careful not to damage speakers.

4. Remove the alarm speaker cable by lifting up from connector J2 on the

UIF PCB.

6-6
 Section 6: Disassembly Guide

6.7 REMOVING THE SPO2 PCB AND SPO2 CONTROLLER PCB

1. Complete the procedure in paragraph 6.5.

2. Remove the rear panel, rear-panel insulator, and NEW

PATIENT/NEONATAL button by lifting up and rotating out of the
chassis channel guides as illustrated in Figure 6-7.

Rear panel

Rear panel insulator

SpO2 PCB
SpO2 controller PCB

NE
LLC
OR
Sym
pho
ny
N-3
000

Pemm stud

Figure 6-7: Rear Panel and SpO2 Module Disassembly

3. Remove the SpO 2 PCB and the SpO 2 Controller PCB by disconnecting
them from the Pemm studs on the UIF PCB. Pull up on the top board
from the right side to disconnect from the Pemm studs.

4. To remove the SpO 2 PCB from the SpO 2 Controller PCB, unsnap the
SpO 2 PCB from the Pemm studs on the SpO 2 Controller PCB.

6-7
Section 6: Disassembly Guide

6.8 REMOVING THE COMMUNICATIONS PCB

1. Complete the procedures in paragraph 6.6 and step 2 of paragraph 6.7.

2. Using a 1/4 inch socket or needle-nose pliers, remove the

Communications PCB by removing the four 1/4-inch nuts that secure it
to the UIF PCB (Figure 6-8). After removing the nuts, lift straight up.

Communications PCB

1/4-inch nut

Jumper J6

NE
LLC
OR
Sym
pho
ny
N-3
000

Top enclosure

Figure 6-8: Communications PCB Removal

6.9 REMOVING THE UIF PCB AND DISPLAY PCB

1. Complete the procedures in paragraphs 6.7 and 6.8.

2. Remove the right-side panel by lifting it straight up.

6-8
 Section 6: Disassembly Guide

3. Remove the front-panel bezel by gently lifting it up and rotating it away

from the Display PCB as illustrated in Figure 6-9.

The display PCB is secured to the UIF PCB via the J5 connector. To
remove the Display PCB, the UIF PCB must first be loosened to allow
the Display PCB to be lifted out of the molded chassis housing slots.

J5 connector
UIF PCB Piezo power loss
alarm speaker
Lithium backup
battery
J3
Speaker boost
Control knob lithium battery
ribbon cable

NE
LLC
OR
Sym
pho
ny
N-3
000

J3 connector
PR
INT

Display PCB

Front panel bezel

Figure 6-9: Display PCB and UIF Board Disassembly

4. Using a Phillips-head screwdriver, remove the six screws securing the

UIF PCB to the chassis.

5. Remove the Display PCB by lifting up on the mother board, then pulling
the Display PCB away from the UIF PCB and disconnecting from J5.

6. Disconnect the control knob ribbon cable from J3 on the UIF PCB. Push
the top of the connector down, then pull the cable straight up and out of
the connector.

7. Lift the UIF PCB out of the chassis housing.

8. When replacing the UIF PCB, the Instrument Identification label must
be replaced. Attach the label to the enclosure on the bottom of the unit.
Reset the configuration code if required. Confirm the number using the
service mode menu item 17.

6-9
Section 6: Disassembly Guide

6.10 CONTROL KNOB ASSEMBLY REPLACEMENT

1. Complete the procedure in paragraph 6.9. The top cover appears as

illustrated in Figure 6-10.

Heat shield

Encoder
assembly
NE
LLC
OR
Sym
pho
ny
N-3
000

Top cover

Figure 6-10: Knob Encoder Disassembly

2. Turn the cover right-side-up as illustrated in Figure 6-11 and use a

small, flat blade to gently pry the knob off the shaft. When removing the
knob in this manner, care must be taken not to nick and dent the
surrounding top cover.

Knob

Nut

Metal washer

Elastomeric
washer

Figure 6-11: Knob Disassembly

3. Using a 7/16-inch socket, remove the nut securing the shaft and knob
assembly to the chassis.

6-10
 Section 6: Disassembly Guide

4. Replace the control knob assembly with the elastomeric washer closest to
the plastic chassis. Torque nut to 10 inch-pounds. Replace the heat
shield and white plastic insulator as illustrated in Figure 6-10.

6.11 LITHIUM BATTERY REPLACEMENT

1. Disconnect AC line voltage from the monitor.

2. With the monitor upside down and facing you, open up the chassis as
shown in Figure 6-5.

3. Locate the lithium batteries on the UIF PCB (Figure 6-9). The backup
lithium battery (the larger of the two lithium batteries) is used to supply
backup power to the UIF processor if the lead-acid battery fails during
DC use. It also supplies power to the piezo power loss alarm speaker
during a microprocessor or power failure alarm. The other (smaller)
battery provides additional voltage to power the piezo speaker.

4. Slide battery (or batteries) from underneath the spring clips. Do not
dispose of lithium batteries by placing them in the regular trash. Dispose
of properly or return to Nellcor Puritan Bennett Technical Services for
disposal.

5. Replace batteries, observing correct polarity (positive terminal up).

Ensure that they are secure.

6. Reassemble the chassis.

6.12 REASSEMBLY

Reassemble the monitor by performing the disassembly steps in reverse

order.

1. Ensure that all plastic isolation shields are reinstalled correctly.

2. Ensure that the small wiper fingers that make contact with the side-
panel metalized coating throughout the top chassis fit properly.

3. Ensure that all buttons are seated properly and operate smoothly.

4. All of the side panels have channel guides molded into the top and
bottom chassis to assist in proper location and seating.

5. To install the handle, locate the small spring attached to one side. After
all PCBs and side panels have been properly seated in the top chassis,
install the handle into the cradle in a vertical position. Guide the spring
into the molded channel located at the rear of the top chassis while
leaning the handle to the inside of the unit. When properly seated, the
handle will rotate out with a small amount of spring tension and
naturally return to the vertical resting position.

6. Depending upon the level of repairs, you may have to reconfigure the
monitor’s Internal Configuration Code (ICC) in order to get the monitor
to operate properly. Refer to the service mode section, menu item 21, of
this manual.

6-11
 Section 7: Spare Parts

SECTION 7: SPARE PARTS

7.1 Introduction

7.1 INTRODUCTION

Spare parts, along with part numbers, are shown below. Numbers in
parentheses correspond to those in Figure 7-1.

Item No. Description Part No.

1 Cover, battery 031763
2 Battery, lead-acid, 12V-2Ah 640115
3 Bracket, battery 030487
4 Cover, bottom, monitor 031646
5 Handle, carrying 030783
6 Panel, left, speaker mount 030067
7 Gasket, speaker 032994
8 Speaker, with lead, connector and insulator 033115
9 PCB, communications, EPP SP033446
11 Battery, lithium, small (3V, 12mm) 640112
12 Battery, lithium, large (3V, 23mm) 642002
15 Cover, top, without metal shield 024897
16 PCB, display SP033057
20 Buttons, on/standby and print 030524
21 Buttons, set of 2, alarm limit 030711
22 Knob, control 024138
23 Encoder, with flexible type cable, optical 291169
26 PCB, UIF SP033442-1
27 PCB, SpO2 controller SP030097
28 Panel, rear 030065
29 PCB, SpO2 SP030063
31 Panel, front 033303
33 Panel, right 033101
34 Clip, grounding 031517
35 Button, audible alarm off 031853
36 Cable, 012 CKT, docking connector 030581
37 Gasket, rubber, SpO 2 030974
38 Button, new patient/neonatal 023301
40 PCB, docking connector SP030221

not pictured SPS-N1 power supply 033877

not pictured NPC-NA power cord 071505
not pictured OXISENSOR II assortment pack ASP3
not pictured Cable, EIA-232, serial interface 030604
not pictured Cable, input, sensor SCP10
not pictured Fuse, 1.0A, type-T, 250V, 5x20 mm 691208
not pictured Fuse, 2.5A, type-T, 250V, 5x20 mm 691311

7-1
Section 7: Spare Parts

Figure 7-1 shows the N-3000 expanded view with numbered callouts relating
to the spare parts list.

Rear panel (28)

Battery cover (1)

New patient/neonatal
button (38)
Lead acid battery (2)

Battery bracket (3)

Bottom cover (4)

Carrying handle (5)

Docking connector PCB (40)

SpO2 PCB (29) Left panel (6)

Speaker gasket (7)

Speaker with lead (8)

SpO2 controller PCB (27)

Communications PCB (9)

UIF PCB (26) Lithium battery, small (11)

Lithium battery, large (12)
Docking connector
cable (36)

Grounding clips (34)

Top cover (15)

Audible alarm off button (35)
LLC
NE Display PCB (16)
Optical encoder assembly (23) 000
N-3
OR

SpO2 rubber gasket (37)

Alarm limit
buttons (21)
Control
knob (22) ON/STDBY
Right panel (33) and PRINT
Front panel (31)
buttons (20)

Figure 7-1: N-3000 Expanded View

7-2
SECTION 8: PACKING FOR SHIPMENT
8.1 General Instructions
8.2 Repacking in Original Carton
8.3 Repacking in a Different Carton

To ship the monitor for any reason, follow the instructions in this section.

8.1 GENERAL INSTRUCTIONS

Pack the monitor carefully. Failure to follow the instructions in this section
may result in loss or damage not covered by the Nellcor Puritan Bennett
warranty. If the original shipping carton is not available, use another
suitable carton; North American customers may call Nellcor Puritan Bennett
Technical Services to obtain a shipping carton.

Prior to shipping the monitor, contact your supplier or the local Nellcor
Puritan Bennett office (Technical Services Department) for a returned goods
authorization number. Mark the shipping carton and any shipping
documents with the returned goods authorization number.

8.2 REPACKING IN ORIGINAL CARTON

If available, use the original carton and packing materials. Pack the monitor
as follows:

1. Place the monitor and, if necessary, accessory items in original

packaging.

Figure 8-1: Repacking the N-3000

2. Place in shipping carton and seal carton with packaging tape.

8-1
Section 8: Packing for Shipment

3. Label carton with shipping address, return address and RGA number, if
applicable.

8.3 REPACKING IN A DIFFERENT CARTON

If the original carton is not available:

1. Place the monitor in a plastic bag.

2. Locate a corrugated cardboard shipping carton with at least 200 pounds

per square inch (psi) bursting strength.

3. Fill the bottom of the carton with at least 2 inches of packing material.

4. Place the bagged unit on the layer of packing material and fill the box
completely with packing material.

5. Seal the carton with packing tape.

6. Label the carton with the shipping address, return address, and RGA
number, if applicable.

8-2
SECTION 9: SPECIFICATIONS
9.1 General
9.2 Electrical
9.3 Physical Characteristics
9.4 Environmental
9.5 Alarms
9.6 Factory Default Settings
9.7 Performance

9.1 GENERAL

Designed to meet safety requirements of:

UL 544, CSA-C22.2 No. 601.1-M90, IEC 601.1, IEC 601.1 (type CF),
ISO 9919, RFE per VFG 243, EMC per IEC 801 series.

9.2 ELECTRICAL

Protection Class

Class I: per I.E.C. 601-1, clause 2.2.4

Degree of Protection

Type CF: per I.E.C. 601-1, clause 2.2.26

Lead-acid Battery

Type Rechargeable, sealed, internal

Operating time 4 hours minimum on full charge when

operating standalone;
2 hours minimum when attached to an
N-3100 blood pressure monitor

Recharge period 14 hours for full charge;

6 hours for 1 hour of operating time

Lithium Batteries

3V, 12mm, coin

3V, 23mm, coin

Input Voltage 15VDC

Fuses F1: 1.0A, 250V, Slo-Blow

F2: 2.5A, 250V, Slo-Blow

External Power Supply

Model SPS-N or SPS-N1 AC input: 100–120 VAC, 500 mA (maximum),

50/60 Hz

9-1
Section 9: Specifications

9.3 PHYSICAL CHARACTERISTICS

Dimensions 6.8 cm x 23.9 cm x 14.7 cm

(2.65 in. x 9.41 in. x 5.79 in.)

Weight 1.8 kg (3.96 lb.)

9.4 ENVIRONMENTAL

Operating Temperature 5 ° to 40 °C (+41 °F to +104 °F)

Storage Temperature -40 ° to +70 °C (-40 °F to +158 °F)

Operating Altitude -396m to +3,139m (-1,300 ft. to +10,300 ft.)

Relative Humidity 15%RH to 95%RH, noncondensing

9.5 ALARMS
Alarm Limit Range

% Saturation 20–100%

Pulse Rate 30–250 bpm

9.6 FACTORY DEFAULT SETTINGS

Factory Default Alarm Settings

Adult Neonate
SpO 2 Upper Alarm Limit: 100% 95%
SpO 2 Lower Alarm Limit: 85% 80%
Pulse Rate Upper Alarm Limit: 170 bpm 190 bpm
Pulse Rate Lower Alarm Limit: 40 bpm 90 bpm

General Factory Default Settings

Default Setting
Operating Mode: Adult-Pediatric
Pulse Beep Volume: 57.5 dB(A) at 1 meter (step 6)
Audible Alarm Volume: 61 dB(A) at 1 meter (step 8)
Audible Alarm Silence Period: 60 seconds
Alarm Silence Reminder: ON
Latching Alarms: OFF
Trend Format: 10-second averaged (Format 1)
Serial Port Baud Rate 19,200 bits per second

9-2
 Section 9: Specifications

9.7 PERFORMANCE

Range

Saturation: 0–100%

Pulse Rate: 20–250 bpm

Accuracy

SpO 2

Adults: 70–100% ± 2 digits

0–69% unspecified
Neonatal: 70–95% ± 2 digits
0–69% unspecified

Accuracies are expressed as plus or minus “X” digits (saturation percentage

points) between saturations of 70–100%. This variation equals plus or minus
one standard deviation (1SD), which encompasses 68% of the population. All
accuracy specifications are based on testing the subject monitor on healthy
adult volunteers in induced hypoxia studies across the specified range. Adult
accuracy is determined with OXISENSOR II D-25 sensors. Neonatal accuracy
is determined with OXISENSOR II N-25 sensors. In addition, the neonatal
accuracy specification is neonatal blood on oximetry measurements.

Pulse Rate (SpO2 optically-derived) 20–250 bpm ± 3 bpm

Accuracy is expressed as plus or minus “X” bpm across the display range.
This variation equals plus or minus 1SD, which encompasses 68% of the
population.

9-3
APPENDIX
A1 Integrity Tests
A2 Error Types
A3 User Correctable Error Codes
A4 Failure Error Codes
A5 Internally Corrected Error Codes

A1 INTEGRITY TESTS

The N-3000 routinely performs internal system integrity tests to verify and
monitor proper operation. As a result, error codes are recorded in the monitor
internal Error Log and codes may be displayed on the monitor front-panel
display. These error codes help establish a starting point for troubleshooting
the N-3000.

Failure error codes are produced by the N-3000 when one of the following
automatic integrity tests detects an error:

• POST (Power-On Self-Test) and Watchdog: The POST verifies processor

memory, display, speaker, communications, time sense device, control
logic, and SpO 2 hardware. The watchdog circuit monitors the operational
status of the processor.

• Background Test: Background tests are periodically run during normal

operation and check the memory integrity, processor operation, and
secondary lithium battery voltage. Internal communication variables and
parameters are checked for the appropriate values and timeliness.

• Failure Error Detection: A failure error may occur at any time. The
failure error detection process attempts to make an entry into the error
log, displays an error code, sounds an alarm, and places the instrument
into a state (including ceasing monitoring) that minimizes the chance of
additional risk to the patient or caregiver.

A-1
Appendix

A2 ERROR TYPES

There are six classes of errors in the N-3000, as indicated in Table A-1.

Table A-1: Error Types

Error Type Description

1. Generic POST/ In this case, nothing may happen, or a shrill

processor failure. continuous alarm may sound and the display may go
blank. This represents a severe hardware failure. For
example, the UIF processor could not activate the
display or speaker facilities.

2. Initialization An EEExxx code representing the failure is displayed

failure. and a low-priority alarm sound is produced, but no
entry is made in the Error Log. POST has proceeded
to the point that the UIF processor has control of the
display and speaker facilities. The error cannot be
logged because the Error Log portion of the EEPROM
has failed, or internal communications to the Error
Log cannot be established.

3. Failure error at An EEExxx code representing the failure is displayed,

the end of a low-priority alarm sound is produced, and a “failure”
initialization or class error entry is made in the Error Log.
during steady
state operation.

4. Internally These errors do not appear on the display, neither do

corrected error. they cause an alarm. However, they are entered in the
Error Log. These errors represent events that have
occurred in the instrument that are undesirable, but
for which the instrument has effective means of
recovery. This includes such things as watchdog
resets, data stream restarts due to data under-run or
stoppage, and resource exhaustion, for example, not
enough memory buffers or not enough CPU cycles.

5. User-correctable An EEE0xx code representing the failure is displayed

error. and a low-priority alarm sound is produced, but no
entry is made in the Error Log. These errors represent
hardware failure conditions that can be corrected by
the user, such as replacing a faulty sensor or cable.
They are not logged because they are caused by
equipment external to the N-3000. They are readily
identified by the 0 leading digit in the error number
displayed along with EEE (failure errors have a
leading digit other than 0).

6. Unexpected loss This results in a shrill, pulsing alarm sound. Nothing

of power. is logged in the Error Log and the display is blank
because the primary power in the instrument has
failed. This alarm is powered by the secondary back-
up lithium batteries located on the UIF board.

In all cases, an attempt to store an error in the Error Log may fail due to
failure or corruption of the Error Log in EEPROM. This condition alone does
not constitute a failure error and operation of the instrument proceeds as if
the error has been successfully logged.

A-2
 Appendix

A3 USER-CORRECTABLE ERROR CODES

The error codes listed in Table A-2 are user-correctable.

Table A-2: N-3000 User-Correctable Error Codes

Error Code Explanation

055 Current user input values (limits, volumes, times) have been
lost during an internal reset and the unit has returned to
power-on defaults.

058 Alarm and beep volume, audible alarm silence duration and
operating mode have returned to power-on defaults due to an
internal instrument reset.

081 Cannot calibrate sensor.

A4 FAILURE ERROR CODES

Table A-3 lists the possible failure error codes in numerical order. Refer to
Table 5-3 for a list of corrective measures.

Table A-3: N-3000 Failure Error Codes

Error Code Explanation

114 UIF excessive watchdog resets.

108 Battery/Power management failure.
109 Stackbus gating failure.
110 Lithium battery voltage too low.
111 UIF unknown POST failure (typically, processor derail or
memory corruption during POST).
151 UIF startup problem, missing resource, or unexpected state
during module initialization.
159 Unable to complete operation. Institutional parameters are in
unknown state.
175 UIF unable to send data over internal stack bus.
176 UIF unable to receive data over internal stack bus.
177 UIF unable to communicate with stacked instruments
178 EEPROM CRC failure (configuration EEPROM).
179 Missing or non-responding module.
183 Illegal operating mode change.

A-3
Appendix

Table A-3: N-3000 Failure Error Codes - Continued

Error Code Explanation

189 UIF RTC failure.

192 Duplicate node detected.
195 Incompatible software.
196 Illegal mode combination in stack.
203 SpO 2 controller failure.
204 SpO 2 digital section failure.
205 SpO 2 controller clock failure (check SpO 2 digital board clock
select jumper and digital board to analog board connection).
206 SpO 2 processor clock failure.
211 SpO 2 unknown POST failure.
275 SpO 2 unable to send a command to UIF module.
276 SpO 2 commands physically but not logically accepted by UIF
module or SpO 2 receiver broken.
283 Illegal operating mode change.

A5 INTERNALLY CORRECTED ERROR CODES

Internally corrected error codes are not normally displayed. These errors are
logged on the internal Error Log, then the N-3000 watchdog circuitry resets
the monitor. They can be accessed only by using the Service Mode (menu
items 7 through 16) as indicated in Paragraph 4.3, Service Mode.

Table A-4 lists the internally corrected error codes in numerical order. It is
not normally necessary for service personnel to access the Error Log.
However, if you find it necessary to contact Nellcor Puritan Bennett
Technical Services or your local Nellcor Puritan Bennett representative, they
may request information from the Error Log.

Table A-4: N-3000 Internally Corrected Error Codes

Error Code Explanation

101 General failure of UIF Generic POST.
125 UIF cannot allocate a resource (ran out of a dynamic resource,
memory corruption during initialization, or a logic error
resulting from a low-probability combination of events that did
not appear in unit or validation testing).
126 UIF stack overflow.
150 UIF general watchdog reset.
152 UIF memory corruption.
153 UIF unexpected interrupt.

A-4
 Appendix

Table A-4: N-3000 Internally Corrected Error Codes - Continued

Error Code Explanation

154 UIF RTXC executive function failed.
156 UIF stack communication bus common code failed.
157 UIF state machine illegal transition or unknown state.
180 External Port Service internal error (RS232 handler).
184 UIF Data stream or Reply timeout.
225 SpO 2 can’t allocate a resource.
226 SpO 2 stack overflow.
250 SpO 2 general watchdog reset.
252 SpO 2 memory corruption.
253 SpO 2 unexpected interrupt.
254 SpO 2 RTXC executive function failed.
256 SpO 2 communication bus common code failed.
257 SpO 2 state machine illegal transition or unknown state.
278 SpO 2 cannot get power-on defaults from EEPROM or they are
invalid (bad values or low-limit above high-limit).
283 Operating mode changed during internal reset.
285 SpO 2 Controller PCB failure.
286 SpO 2 PCB failure.
287 SpO 2 detected failure of other system component (UIF PCB,
UIF software, or communication problem).
288 SpO 2 module failure (cannot determine whether SpO2
Controller PCB or SpO2 PCB).

A-5
TECHNICAL SUPPLEMENT
S1 Introduction
S2 Oximetry Overview
S3 Stackbus Interconnect
S4 Circuit Analysis
S5 Schematic Diagrams

S1 INTRODUCTION

This Technical Supplement provides the reader with a discussion of oximetry

principles and a more in-depth discussion of N-3000 circuits. A functional
overview and detailed circuit analysis are supported by block and schematic
diagrams. The schematic diagrams are located at the end of this supplement.

S2 OXIMETRY OVERVIEW

Pulse oximetry is based on two principles:

• Oxyhemoglobin and deoxyhemoglobin differ in their absorption of red

and infrared light (spectrophotometry).

• The volume of arterial blood in tissue (and hence, light absorption by

that blood) changes during the pulse (plethysmography).

A pulse oximeter determines SpO2 by passing red and infrared light into an
arteriolar bed and measuring changes in light absorption during the pulsatile
cycle. Red and infrared low-voltage light-emitting diodes (LEDS) in the
oximetry sensor serve as light sources; a photodiode serves as the photo
detector.

Because oxyhemoglobin and deoxyhemoglobin differ in light absorption, the

amount of red and infrared light absorbed by blood is related to hemoglobin
oxygen saturation. To identify the oxygen saturation of arterial hemoglobin,
the monitor uses the pulsatile nature of arterial flow. During systole, a new
pulse of arterial blood enters the vascular bed, and blood volume and light
absorption increase. During diastole, blood volume and light absorption reach
their lowest point. The monitor bases its SpO2 measurements on the
difference between maximum and minimum absorption (that is,
measurements at systole and diastole). By doing so, it focuses on light
absorption by pulsatile arterial blood, eliminating the effects of nonpulsatile
absorbers such as tissue, bone, and venous blood.

S2.1 Automatic Calibration

Because light absorption by hemoglobin is wavelength-dependent and

because the mean wavelength of LEDs varies, an oximeter must know the
mean wavelength of the sensor’s red LED to accurately measure SpO 2.
During manufacturing, a resistor in the sensor encodes the mean wavelength
of the red LED. During monitoring, the instrument’s software reads this
resistor and selects coefficients that are appropriate for the wavelength of
that sensor’s red LED; these coefficients are then used to determine SpO 2.
This resistor is read when the monitor is turned on, periodically thereafter,
and each time a new sensor is connected.

Additionally, to compensate for differences in tissue thickness, the intensity

of the sensor’s LEDs is adjusted automatically.

S-1
Technical Supplement

S2.2 Functional Versus Fractional Saturation

This monitor measures functional saturation — oxygenated hemoglobin

expressed as a percentage of the hemoglobin that can transport oxygen. It
does not detect significant amounts of dysfunctional hemoglobin, such as
carboxyhemoglobin or methemoglobin. In contrast, hemoximeters such as the
IL482 report fractional saturation — oxygenated hemoglobin expressed as a
percentage of all measured hemoglobin, including measured dysfunctional
hemoglobins. To compare functional saturation measurements to those from
an instrument that measures fractional saturation, fractional measurements
must be converted as follows:

fractional saturation
functional saturation = x100
100 - (% carboxyhemoglobin + % methemoglobin)

S2.3 Measured Versus Calculated Saturation

When saturation is calculated from a blood gas partial pressure of oxygen

(PO 2), the calculated value may differ from the SpO 2 measurement of a pulse
oximeter. This usually occurs because the calculated saturation was not
appropriately corrected for the effects of variables that shift the relationship
between PO 2 and saturation (Figure S2-1): pH, temperature, the partial
pressure of carbon dioxide (PCO 2), 2,3-DPG, and fetal hemoglobin.

100 pH
Temperature
PCO2
2,3-DPG
Fetal Hb
Saturation (%)

pH
50 Temperature
PCO2
2,3-DPG

0
50 100
PO2 (mmHg)

Figure S2-1: Oxyhemoglobin Dissociation Curve

S3 STACKBUS INTERCONNECT

Stackbus is the term for the communication interconnect between the N-3000
modules and also between the N-3000 and N-3100 instruments.

The internal stackbus is used for communications between the UIF PCB and
the SpO 2 module. Information is transmitted over a single PCB trace using
the Arcnet (discussed in paragraph S4, Circuit Analysis) local area network
standard as the message protocol.

S-2
 Technical Supplement

The external stackbus is used for communications between the N-3000 and
the N-3100. Information is exchanged over two pins on the N-3000 docking
connector and two sockets on the N-3100 upper docking connector. As with
the internal stackbus, the Arcnet local area network standard is used as the
protocol. RS-485 drivers and receivers are used for signaling. A proximity
sensor in the bottom of the N-3000 or N-3100 detects when the monitor is
docked, enabling the stackbus signals.

Access to the stackbus is accomplished through token passing. A token

designates which station (module or instrument) has control of the stackbus.
The token is passed in a circular manner from station to station. The station
holding the token has the exclusive right to transmit onto the stackbus, but
the right to transmit may be temporarily donated to another station to
acknowledge a transmission by the token holder. The token holder must
relinquish control of the stackbus by passing the token to the next station on
the loop within a specified period of time. During normal operation, the right
to access the stackbus passes from station to station in a continuous,
consistent manner.

All instruments participate in the loop when stacked and powered-on.

Maintenance of the token passing, loop initialization, lost token recovery, and
the addition of new stations is implemented in the N-3000’s UIF and SpO 2
modules and in the N-3100 by the specialized devices and system software.

S4 CIRCUIT ANALYSIS

This section provides a descriptive overview of the N-3000 modular design, as

well as a circuit description.

S4.1 Functional Overview

The monitor functional block diagram is shown in Figure S4-1. Central to the
PCB modules is the UIF module. This module receives power from an
external AC source or battery via the docking connector. It supplies power to
the other modules connected to it, while also communicating with them via
the stackbus. It controls user interface and network gateway functions.

Connected to the UIF module is the SpO2 module, which consists of two
PCBs: the SpO 2 Controller and the SpO 2 PCB. The SpO2 Controller board
contains the micro controller, memory system, internal stackbus interface,
and other control logic. The SpO2 PCB contains all the analog signal
conditioning and control hardware necessary to measure SpO2 . The two
boards are electrically connected by a single interface connector.

The Communications module allows messages to be sent to a host computer

using asynchronous serial communications. All communications signals on
the Communications module originate from the UIF module.

The Display module contains annunciators and push buttons, allowing the
user to access information and to select various available parameters. The
Display PCB contains SpO 2 and heart rate LEDs and their associated driver
circuits. Front-panel switches also allow the user to turn the unit on and off,
to set alarm limits and to print data. The Display PCB is connected to the
UIF module via a 14-pin connector.

S-3
Technical Supplement

SpO2
Module

External
Power
Supply Communi-
Docking UIF
Connector Module cations
Module
Battery

Display Module –
Visual Annunciators and Controls

Figure S4-1: N-3000 Functional Block Diagram

S4.2 Circuit Description

The following paragraphs discuss the operation of each of the printed circuit
boards within the N-3000 oximeter. (Refer to the appropriate schematic
diagram at the end of this supplement, as necessary.)

S4.2.1 SpO 2 Module

a. Isolated Power Supply

Transformer T1 and associated components comprise the isolated power

supply circuitry of the SpO2 module (see sheet 1 of the schematic diagram).
This power supply is a pulse-width modulated, current-mode, switching
supply. In this circuitry, controller U4 is synchronized to a programmable
clock frequency, ANALOG CLK (U4, pin 4). Timing for the isolated circuitry
is derived from the switching frequency of the power supply, hence ANALOG
CLK is used to control front-end aliasing. If no ANALOG CLK signal is
available, R13 and C8 provide a default timing circuit for the U4 controller.

Two parallel FETs, Q7, drive the T1 transformer in flyback mode, channeling
the current through sense resistors R23 and R133. Any inductive spike
created by the leakage inductance of the T1 transformer is filtered out of the
circuit by R105 and C9.

Feedback for the U4 controller is optocoupled through one-half of U34. This

controls the circuit pulse width, which also maintains the isolated VCCI at
5 volts. Components R68, R69, R70, C45, and CR8 detect the value of VCCI
and increase the output of the optocoupler when it (VCCI) is over 5 volts.

S-4
 Technical Supplement

The transformer flyback pulse is rectified by CR7 and filtered by C12, C57,
and R5 to create VCCI. The other two transformer windings have three times
as many turns as the VCCI winding. These windings are rectified by CR5 and
CR6 to achieve ±15 volts during the flyback cycle. These supplies are then
regulated by U2 and U15 to ±12 volts.

Normal transformer signals are filtered out of the circuitry by C55, R110,
CR2, Q3, R38, C14, Q6, R53, and R49. However, the Q7 turn on transition is
a direct result of the ANALOG CLK signal. This creates the isolated clock
signal (ISO CLK) and guarantees a consistent output pulse time independent
of the pulse width modulation and inductive transient changes.

b. Timing

The ISO CLK is divided by U29 and decoded by U1 and U30 to create the
timing signals used throughout the isolated section of the circuit. The timing
diagram (Figure S4-2) shows the result of this decoding. One complete cycle
of the front end takes 16 ISO CLK cycles.

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Analog Clk

Off/On

Red/Ir

Ir/Red

IRSMP L

REDSMP L

Figure S4-2: Timing Diagram

c. Microprocessor Control of Isolated Circuitry

Controller U10 (sheet 2 of schematic) is an Octal 8-bit DAC. The reference

voltage for U10 is 5 volts, created by U39. Two U10 outputs, VOUTA and
VOUTB, are used to program the LED outputs for the IR and RED channels.
The other six signal lines are used as logic lines. Five control amplifier gain:
PD0 and PD1 select the predemodulation gain, while DM0, DM1, and DM2
control the demodulated gain. The remaining signal line, CAL (U10, pin 18),
selects the calibration setting.

d. LED Drive

The LED drive circuitry is shown in the lower left corner of the schematic
diagram, sheet 2. Signal outputs from U10 — RED LED and IR LED — are
used to control LED brightness. These signals are multiplexed by U31 and
buffered by one-half of U32. A voltage divider circuit consisting of R101 and
R102 divide the multiplexed signal down to the proper voltage to use as a
reference for the other half of U32.

Additionally, R92 provides a path for stray current during the off period to
ensure that the LEDs are truly off. Components R97, R98, and Q12 provide
secondary protection against over-current drive by disabling the control op
amp if the voltage goes above 0.9 volts.

S-5
Technical Supplement

Components R30 and C24 filter any high-frequency noise on VCCI that is
beyond the bandwidth of U32. Finally, Q13, R104, and R105 turn the LEDs
off between pulses.

e. Differential Input Amplifier

Input op amp U23 converts the differential current to a voltage. One side of
the output is coupled through capacitor C48 while the other output is used as
a reference that is switched by U24 onto R78 only during one channel on/off
cycle. This AC couples only one channel.

Low frequency noise on the other channel is eliminated also since the LED-off
output for both channels is the same. This switched AC coupling removes the
DC without resulting in channel crosstalk. The resulting AC-coupled signal
and reference are switched through U25 to the input of differential amplifier
U21 when the patient module is plugged in.

If the cable is plugged in, U25 selects the output of the preamp and ground as
the input to U21. AC coupling is performed to keep crosstalk from the
preamped AC signal. Differential amplifier U21 has a programmable gain of
1, 4, 16, or 64, depending upon the state of PD0 and PD1.

f. Synchronous Demodulator and Gain

If calibration is not selected, the output of U21 is directed through U26 to

filter U27 to eliminate high-frequency noise. Amplifier U28 is either an
inverting or noninverting amplifier, depending on the state of switch U26.

U3 samples the output to demodulate the two channels. This sample-and-

hold is then amplified by U5 or U6. The gain is 1 or 16, depending upon the
state of DM2 from the U10 controller. The other half of U5 (or U6) drives the
linear opto-isolator to create a current output proportional to the input
voltage. This current has an effective gain of 1, 2, 4, or 8, controlled by DM0
and DM1. U13 converts the current output of the linear opto-isolator (U6) to
a voltage and then to a digital value.

g. Auto Calibration

Switch U26 selects either the differential amplifier (U21) output or the
internal calibration signals as an input to the U27-based filter. If the
calibration input is selected, U24 can select either a zero or test input.

The zero input connects the filter input to ground so the system can calibrate
the no-signal output of the two channels. The test input connects the LED
current waveform to the filter so the demodulator has an output proportional
to the programmed LED current.

h. Nonisolated Power Supply

The power supply creates ±5 volt from the system battery supply. The input
voltage is 8–16 volts, which is filtered and regulated by U19 to create the
+5 volts. U20 converts this input to a regulated -7 volt output that is
regulated to -5 volts by U18.

S-6
 Technical Supplement

S4.2.2 UIF Module

The user interface (UIF), network gateway, and battery charge functions are
controlled by the UIF module. This module provides power to the other
modules within the N-3000, controls communication between each module via
the stackbus, and provides charge control for the lead-acid battery.

a. Power and Battery Charging

Power from the lead-acid battery or the lower docking connector is delivered
via the lower docking board ribbon cable connected to J13. Pin 1 of J13 is
BATTPLUS1 and Pin 6 of J13 is CHARGEBUS. Pin 2 of J13 is earth ground
and Pin 5 is system ground. These pins are defined in table S4-1. Both
CHARGEBUS and BATTPLUS1 are connected using diode isolation and then
connected through the drain of power transistor Q10 and Pin 7 of J13
(BATTBUS) to other stacked instruments.

Power switching and battery charging are controlled by U20, a BQ2001 power
monitor IC.

The BQ2001 power monitor IC has three sources of power input:

CHARGEBUS from the SPS-N or SPS-I power supply, the N-3000 lead-acid
battery, or lithium battery BT1. The ON/STANDBY button is connected to
BQ2001, which controls the gate of power transistor Q10. Processor U3 is also
connected to BQ2001, receiving interrupts and reading data from the BQ2001
status registers when the N-3000 is on.

When the N-3000 is OFF (standby mode) and the ON/STANDBY button is
pressed, the BQ2001 enables transistor Q10 and analog power from either
the CHARGEBUS or the lead-acid battery is supplied to the 5V regulator
(U17 and U18) and the SpO 2 module . It also signals the processor with an
interrupt that there is new data in its status registers for the processor to
read. As soon as the processor powers-up and clears reset, it will process the
interrupt from the BQ2001 and begin to execute its program.

S-7
Technical Supplement

Table S4-1: J13 Inter Stack Connector

Pin No. Pin Description Input/Output/Power

1 Positive battery terminal (fused) Power
2 Chassis (case) ground Power
3 Stackbus differential + I/O
4 Stackbus differential - I/O
5 Digital ground Power
6 Charge bus (15V) Power
7 Battery bus voltage Power
8 Proximity signal Input
9 Not used n/a
10 Not used n/a
11 Not used n/a
12 Battery charge Power

When the N3000 is on and the ON/STANDBY button is pressed, the BQ2001
signals the processor via interrupt that there is data for the processor to read.
When the processor reads the status, it determines that the unit should be
turned off and signals the BQ2001 to disable Q10.

Other sources of interrupt from the BQ2001 are a low voltage from lithium
battery BT1, the application or removal of CHARGEBUS power, and the
lead-acid battery voltage falling below a threshold preset by the processor.

When the SPS power supply is connected to the lower docking connector and
connected to AC, CHARGEBUS has a voltage of 15V ± 0.75V. This powers the
battery charge overcurrent and overtemperature circuitry. The BQ2001
controls battery charging. When the processor senses that the battery needs
charging, it tells the BQ2001 to turn on transistor Q5 for a programmed
length of time. The BQ2001 will continue charging the battery as long as
there is CHARGEBUS available and its internal charge time register has not
expired regardless of the mode of the N3000, unless it is told to stop by the
processor or it senses that the over-temperature circuit has tripped.

The battery charging circuitry is a constant voltage charger. When the

battery is discharged, its output voltage is low (about 10V) and the maximum
charge rate (approximately 350mA) is applied to it. As the battery charges,
its output voltage rises, reducing the amount of current delivered to it by
CHARGEBUS. When the battery is fully charged (about 14V), the charge rate
decreases to 0 mA.

The over-temperature cutoff circuitry is physically located close to the power

transistor used to charge the battery by the BQ2001. When the area around
the transistor approaches 70° C, the circuit will signal the BQ2001 to stop
charging. When the transistor cools, charging is resumed.

To protect the battery, a thermal cutoff switch is located on the docking

connector close to the lead-acid battery compartment. When the temperature
in the battery compartment approaches 50° C, the switch opens to prevent
damage to the lead-acid battery.

S-8
 Technical Supplement

b. Processor

The processor for the UIF PCB is U3, a Motorola MC68331 IC. This processor
uses a 32-bit CPU and contains several submodules, including pulse-width
modulators, internal RAM, and a Queued Serial Module (QSM). The
processor also contains a non-multiplexed, data/address bus and input/output
timer pins.

The processor generates chip selects, address lines, data direction, and data
strobes for communicating with its peripherals over its bidirectional, 16-bit
data bus D15 through D0. The chip select outputs are /CSBOOT and /CS0
through /CS8. The address lines are A0 through A18. The data direction is
generated by U3 on R/W. The data strobe for indicating valid data is
generated on /DS. Using these control lines, the processor is capable of
reading from or writing to any of the peripherals attached to its data bus.
Data transfers are either 16-bit (D15 through D0) or 8-bit (D15 through D8).

A 32.679 kHz source clock signal for the processor is produced by stackbus
adapter U14 from crystal Y3. System clock frequency is chosen by software.

c. Processor Peripheral ICs

Processor U3 uses serial and parallel peripheral ICs.

The serial peripheral ICs communicate with the processor through the 68331
Queued Serial Module (QSM). These ICs are the Real Time Clock (RTC), the
Electrically Erasable Read Only Memory (EEROM) and the display
controllers located on the Display PCB.

The parallel peripheral ICs communicate with the processor through a non-
multiplexed data bus. The ICs are processor code PROM U10, processor
RAMs U13 and U23, Arcnet communications IC U6, digital-to-analog
converter U5, analog-to-digital converter U27, stackbus adapter U14, BQ2001
power management chip U20, and UART (Universal Asynchronous Receiver
Transmitter) U24.

Real Time Clock — The clock is a continuously running IC used by the

processor to maintain time and date information. When the N-3000 is not on,
the RTC is maintained by lithium backup battery BT1.

Electrically Erasable Read Only Memory — The EEROM is used by the

processor to store institutional defaults and system error code data.

Display Controllers — These controllers are used by the processor to

display data on the display board.

Processor Code PROM (U10) — The PROM contains the program that the
processor uses to perform the user interface and gateway functions for the
N-3000. Processor U3 address lines A1 through A17 are connected to PROM
addresses A0 through A16, allowing even word address access to the PROM.
To allow the use of either a 256K x 16 or 128K x 16 PROM at U10, Pin 43 of
U10 is connected to J10 Pin 2. On a 256K x 16 PROM, Pin 43 will be PROM
address A17. On a 128K x 16 PROM, Pin 43 will be an active high output
enable. Address line A18 from U3 is connected to J10 pin 1 and VDD is
connected to J10 pin 3. Attaching a jumper between J10 pins 1 and 2 will
connect U3 address line A18 to PROM address A17 to address all 256K words
in a 256K x 16 PROM. Connecting a jumper between J10 Pins 2 and 3 will
connect Pin 43 to VDD for the active hi output enable of a 128K x 16 PROM.

S-9
Technical Supplement

The PROM chip select is connected to the /CSBOOT signal (Pin 112) of U3. At
system reset, this signal defaults to decode address %00000 for a block of 1
megabyte, held active for 13 wait states and gated with the processor address
strobe. The output enable of the PROM (pin 22) is connected to ground
through R8 to allow data to be gated onto the data bus as soon as the
/CSBOOT signal goes active. After a system reset, /CSBOOT is configured to
have one wait state and to be active only for the address range of the PROM.

Processor RAM (U13 and U23)— The RAMs are used by the processor to
store program variables, values and trend data. Each is 128K x 8, arranged to
provide 128K x 16 bits of RAM for use by the processor. U3 address lines A17
through A1 are connected to both RAMs’ address lines A16 through A0. U3
data bus lines D15 through D8 are connected to U13 data bus lines D7
through D0 for the upper 8 bits of data. U3 data bus lines D7 through D0 are
connected to U23 data bus lines D7 through D0 for the lower 8 bits of data.

The active low chip select inputs of U13 and U23 are connected to the CS0
and CS1 chip select outputs of U3. The active high chip select inputs of U13
and U23 are connected to the active low system reset to prevent writing to
the RAM while the system power is coming on or while the watchdog reset is
active. The output enables of U13 and U23 are connected to digital ground.
The write enable inputs of U13 and U23 are connected to the data direction
(R/-W) output of U3. At system reset, the RAM chips are disabled and CS0
and CS1 from U3 are disabled. After system reset, CS0 and CS1 are
configured to be gated with data strobe output DS from U3.

When the N-3000 is in STANDBY, RAM power is supplied by the backup

battery output of the BQ2001. Power is maintained by the N-3000 lead-acid
battery and, in the event that the lead-acid battery becomes discharged or is
removed, by the lithium backup battery BT1.

Arcnet controller — U6 is the Arcnet controller (COM20020). It is used by

the processor to implement the stackbus protocol. It is an 8-bit, memory-
mapped device that manages the stackbus communications physical
implementation along with the stackbus adapter. It is connected to the upper
8 bits of the processor data bus to allow for byte operations from the
processor. The chip select for U6 is processor pin /CS4.

Digital to Analog Converter — DAC U5 is an 8-bit converter used by the

processor to control speaker volume. It is a write-only, memory-mapped
peripheral connected to the upper 8 bits (D15 through D8) of the processor
data bus. It converts the 8-bit data value written into it by the processor to
control the amplitude of the square wave generated by processor output OC2.
The resultant amplitude controlled square wave is then sent to audio
amplifier U4 to drive the 8-ohm speaker. The chip select for U5 is processor
pin /CS5.

Analog to Digital Converter — ADC U27 is an 8-bit analog to digital

converter used by the processor to measure three different analog voltages. It
is a read-only, memory-mapped peripheral connected to the upper 8 bits (D15
through D8) of the processor data bus. The analog voltage values indicate
which display board button has been pressed, what the combined voltage of
both lithium batteries is, and the value of the analog voltage being supplied
from transistor Q10 to the SpO2 module and 5V regulator chips (U17 and
U18). The chip select for U5 is processor pin /CS7. The selection of analog
voltages to read is controlled by processor outputs PWMA and PWMB which
must be set up prior to accessing U27.

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 Technical Supplement

Stackbus Adapter — Adapter U14 is an FPGA (field programmable gate

array) used by the processor to control the hub functions for both the internal
and external stackbus. It also decodes the knob movement as well as
providing a 32.679kHz source clock. It is an 8-bit, memory-mapped peripheral
connected to the upper 8 bits (D15 through D8) of the processor data bus. The
internal stackbus provides the communications for the UIF module and the
SpO 2 module. The external stackbus is used to communicate with other
instruments when the unit is used in the stack configuration. The chip select
for U14 is processor pin /CS3.

Universal Asynchronous Receiver Transmitter — UART U24 is an

industry standard 16C550. It is an 8-bit memory-mapped peripheral
connected to the upper 8 bits (D15 through D8) of the processor data bus. It
contains two 8-byte FIFOs, one for transmit and one for receive, a baud rate
generator, and several programmable I/Os for enabling isolated power on the
communications module, serial communication handshaking, and alarm
active signaling. The chip select for U24 is processor Pin /CS6.

SpO2
COM Module
20020
U8 Communi-
cationbus Internal Stackbus
Adaptor
(FPGA)
U14 485 External Stackbus
Driver
U15
UIF Board
Docking Stacked
Connector Instruments

Figure S4-3: Internal/External Stackbus Connections

d. Processor Support ICs

The processor support ICs are used to monitor the processor and its power
supply, resetting U3 when necessary, and to sound an alarm using piezo
speaker Y1 when the processor appears to be inoperative or when the unit
has had an unexpected power loss.

The processor support ICs are watchdog timer U21 and the processor/power
fail circuitry consisting of U16, U1, U2, U11, U22, and U29.

Watchdog Timer — Timer U21 ensures that processor U3 does not operate
and switches the backup battery power from U20 to the RAMPWR supply
when the +5 volt supply is below its lower regulation limit. This chip holds
U3 in reset until the power supply is above its lower regulation limit.

The watchdog timer also resets the processor if the processor input signal
(CLRWD) is not toggled within a timeout period controlled by the watchdog
oscillator circuitry. When the watchdog times out, it generates a signal that
causes the piezo power loss alarm speaker to emit a tone. The timeout also
causes the display to go blank and generates a reset to U3. The tone
continues until the watchdog is cleared due to:

• activity on the CLRWD signal line

• pressing the ALARM SILENCE button
• removing power from the circuit

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Technical Supplement

Timer U21 also switches the backup battery power from U20 to RAMs U13
and U23, the processor/power fail circuitry, when the +5V supply is below its
lower limit.

Processor/Power Fail Circuitry — This circuitry sounds the piezo speaker

if the processor fails to operate or the 5V power unexpectedly falls below its
lower regulation limit.

e. Connectors

This section describes UIF connectors and pinouts other than the docking
connector J13.

J8 — J8 is a 40-pin daughter board connector that interfaces the UIF module

to the communications board. This board uses only the first 16 pins on the
connector.

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 Technical Supplement

Table S4-2: J8 Connector

Pin No. Pin Description Input/Output/Power

1 Ground Power
2 Ground Power
3 UARTTXD (RS232/422 only) O
4 Ground Power
5 UARTRXD (RS232/422 only) I
6 Internal Stackbus I/O
7 QData (sub module detection) I
8 UARTDTR (RS232/422 only) O
9 Ground Power
10 VCC Power
11 VCC Power
12 VCC Power
13 VCC Power
14 Ground Power
15 External Communications Standby O
16 UARTDSR (RS232/422 only) I
17 Not Used n/a
18 NURSECALL O
19 Not Used n/a
20 Ground Power
21 Interrupt from second COM20020 I
22 Analog power Power
23 Ground Power
24 Ground Power
25 Reset O
26 DSL (data strobe low) O
27 SDCK (used for sub module detection) I
28 Chip select O
29 Read/Write Strobe O
30 D14 I/O
31 D12 I/O
32 D15 I/O
33 A1 O
34 D13 I/O
35 A2 O
36 D10 I/O
37 D8 I/O
38 D11 I/O
39 A0 O
40 D9 I/O

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Technical Supplement

J12, J22 — These are two identical connectors that interface to the SpO2
module. Power and stackbus signals are sent to these modules. Additionally,
a connection between these two connectors allows the modules to
communicate without stackbus, if necessary.

Table S4-3: J12, J22 Inter Module Connector

Pin No. Pin Description Input/Output/Power

1 Ground Power
2 VDD Power
3 Internal stackbus I/O
4 VDD I/O
5 Signal line from expansion module to SpO2 I/O
6 VDD I/O
7 Signal line from SpO 2 to expansion module I/O
8 Module reset I/O
9 High voltage power Power
10 Ground Power
11 Not used n/a
12 Ground Power
13 Not used n/a
14 Ground Power

J5 — Connector J5 connects to the display board, which allows the UIF

module to control the monitor display. Signals at this connector include
power, serial clock and data lines, button signal, and charging battery
indicator current.

Table S4-4: J5 Display Connector

Pin No. Pin Description Input/Output/Power

1 Power (from switch–controlled by external watchdog) Power
2 Power (from switch–controlled by external watchdog) Power
3 Power for green Power On LED Power
4 Serial clock O
5 LED drivers latch enable O
6 Data out O
7 Power to Battery Charging LED Power
8 Not used n/a
9 On button I
10 Button voltage I
11 Not used n/a
12 Charge bus voltage Power
13 Digital ground Power
14 Digital ground Power

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 Technical Supplement

J2 — Connector J2 connects the UIF board to the monitor speaker.

Table S4-5: J2 Speaker Connector

Pin No. Pin Description Input/Output/Power

1 Differential speaker signal + I/O
2 Differential speaker signal – I/O

J3 — Knob connector J3 allows the U3 controller to detect knob movement.

Table S4-6: J3 Knob Connector

Pin No. Pin Description Input/Output/Power

1 Digital ground Power
2 Knob channel B I
3 VDD Power
4 Knob channel A I
5 Chassis (case) ground Power

S4.2.3 SpO 2 Controller

The central processing unit (CPU) for the SpO 2 Controller PCB is the U1
microprocessor. It contains an 8-channel, 10-bit analog-to-digital converter.
Six inputs—ANALOG0 to ANALOG5—are bussed to the analog board
interface connector, J4. Of the remaining signals, ANALOG6 is connected to
Vcc and ANALOG7 is connected to ground. These analog inputs are used
during the POST to verify proper operation.

a. CPU Reset

Voltage monitor U2, shown in the upper left-hand corner of the schematic
diagram, generates the reset for U1. Reset is held low until Vcc raises above
4.6 volts. After Vcc is above 4.6 volts, reset is tri-stated and pulled high by
R10. Note: L1, L2, and L3 provide filtering for Vcc.

b. Program Memory (EPROM)

The program memory chip, U4, provides the SpO 2 controller board with 128K
bytes of memory. This program boot ROM memory can be expanded up to
256K bytes. The CSBOOT signal from U1, which is configured for 16-bit
memory access, provides the enable signal for U4. After system software
comes on, or is booted up, CSBOOT is configured for a start address of 0, a
block length of 256K bytes, both read and write access, and gated with AS.
This configuration provides a program memory range of 00000h through
3FFFF.

The number of wait states needed before the CSBOOT signal is generated
depends upon the U1 clock speed and the speed at which U4 can successfully
perform its functions. With the N-3000, the number of wait states must be set
to 1, based upon a CPU clock speed of 16.0 MHz, maximum, and the U4
access time of 150ns, maximum.

Resistor R22 pulls the U4 OE signal state to low during normal operation. If
this signal state is high, the U4 output is disabled.

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Technical Supplement

c. RAM Memory

The U5 RAM chip provides the SpO2 Controller board with 128K bytes of
memory. The U1 CS0 provides the chip enable signal for U3.

The U3 hardware has an 8-bit wide data path. After boot up, CS0 is
configured as a chip select with a start address of 40000h, block length of
128K, 8-bit port, both bytes access, both read and write access, and gated
with AS. This configuration gives a data memory range of 40000 through
5FFFF.

The number of wait states to generate depends upon the U1 clock speed and
the U3 access speed. The number of wait states for CS0 is set to 0, based on a
U3 access time of 85ns, minimum.

d. Stackbus

The SpO2 controller board also communicates with other boards within the
N-3000 via the stackbus. The stackbus is controlled by the COM 20020
Arcnet controller chip, U6, which is enabled by U1 CS1.

CS1 must be configured as a chip select with a start address of 60000h, block
length of 2k, 8-bit port, both bytes access, both read and write access, and
gated with AS. This configuration maps the stackbus in the memory range of
60000h through 607FFh.

The number of wait states to generate depends on the U1 clock speed. The
number of wait states for CS1 must be set to 2, based upon a CPU clock speed
of 16.0 MHz.

e. Programmable Clock

The clock frequency on the SpO 2 controller board is programmed via

software. The clock signal is labeled CTRL_CLK. The clock circuitry consists
of U7 and U10. One half of U7 takes a 20 MHz input and produces three
output frequencies: 10 MHz, 2.5 MHz, and 1.25 MHz. The 10 MHz frequency
is the clock rate of the programmable down counter, U10. The second half of
U7 takes the terminal count (TC) output of U10 and converts it to a 50% duty
cycle square wave.

The frequency of CTRL_CLK is controlled by an 8-bit number. The bits of this

number are split between two output ports. The lower 5 bits of the number
are programmed on the lower 5 bits of port C. The upper 3 bits of the number
are programmed on the upper 3 bits of port E.

The formula for the CTRL_CLK frequency is: frequency = 5MHz/ (1 + TIME),
where TIME is the 8-bit number output by the CPU. TIME has a valid range
of 1-255. The circuit provides an adjustment range of 19.531 kHz to 2.5 MHz.

The CTRL_CLK signal is input back to U1 Pin 16. During the POST routine,
this pin is used to monitor the programmable clock hardware output to verify
performance.

f. Intermodule Connector

The SpO2 controller board is connected to the UIF board via the J1
intermodule connector. The UIF board provides power to the SpO2 controller.
Stackbus and module synchronization lines are also routed through J1.

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 Technical Supplement

S4.2.4 Communications Submodule

The communications submodule contains circuitry for allowing 1500V

isolated asynchronous serial RS232 or RS422 communications between the
N-3000 UIF module and a host computer, a 1500V isolated nurse call signal
that operates whenever an alarm condition exists, or a 1500V isolated 3.3V
power source for powering remote external serial equipment.

Signals that originate on the UIF board include:

UARTTXD Transmit data from UART

UARTRXD Receive data to UART
UARTDTR Data terminal ready from UART
UARTDSR Data set ready to UART
ALARMACTIVE Prog. I/O from UART
Shutdown Prog. I/O from UART

Connector J5 contains the signals for communicating with the UIF board
(J8), as detailed in Table S4-2.

There is an auxiliary connector, J2, on the communications PCB for future

expansion.

a. Serial Communications

Serial communications are available only when the SPS power supply is
connected to the N-3000 docking connector and plugged into an AC outlet.
When the UIF processor detects that CHARGEBUS is available, it enables
isolation transformer driver U1 (MAX253). This creates power for circuitry on
the isolated (host computer) side of the module. Transmit and Receive data
cross the barrier through optical isolators U5 and U3 (6N136). CTS and RTS
signals cross the barrier through optical isolators U4 and U2 (4N26).

Isolation
transformer
DTR
Transmit data 1
Data terminal ready DSR
2
Data terminal set TXD
Request to send TXD
3
connector

connector
6 pin DIN

RXD
16 pin

Signals from Alarm Active

UIF module
DTR

Five volts DSR

GND
4
Ground
Optocouplers RXD
5

Shut down Isolation barrier ALARM ACTIVE

1500 volts 6

Maximum baud rate: 19.2K

Figure S4-4: Communications Submodule Block Diagram

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Technical Supplement

Selecting RS232 serial signaling is accomplished by moving switches

S1,S3,S5,S7 on SW1 and SW2 to the on position and switches S2,S4,S6,S8 to
the OFF position. This enables U9 and disables U10. With RS232 selected, J1
has the following pinout:

1 DTR
2 DSR
3 TXD
4 GND
5 RXD
6 Nurse Call/3.3V

Selecting RS422 serial signaling is accomplished by moving switches

S2,S4,S6,S8 on SW1 and SW2 to the on position and switches S1,S3,S5,S7 to
the OFF position. This enables U10 and disables U9. With RS422 selected, J1
has the following pinout:

1 TXD-
2 RXD-
3 TXD
4 GND
5 RXD
6 Nurse Call/3.3V

b. Alarm Active/3.3V Power

Isolated alarm active or 3.3 volt power is selectable as a 500mA fused output
on J1 Pin 6. Placing switch block SW3, S1 to the on position, and S2,S3,S4 to
the OFF position, will select the alarm active signal on J1 Pin 6. The alarm
active signal provided is a normally open relay that shorts Pin 6, J1 to Pin 4,
J1 signaling an alarm event.

To select isolated 3.3 volt power, place switch SW3 S1 to the OFF position
and S2,S3,S4 to the on position. This provides up to 100mA of 3.3 volt power.

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 Technical Supplement

S4.2.5 Display Board

The N-3000 display board is the assembly that contains the front-panel
display for the monitor. The display board is connected to and controlled by
the UIF module. The display board block diagram is shown in Figure S4-5.

Digital Displays:
SpO2

Synchronous Display Heart/Pulse Rate

Serial Interface Driver
Respiration

Indicators:
Motion
Pulse Amplitude Pulse Search
Plethysmograph
Indicator
Alarm Silence
Stacked
UIF Neonatal
Leads Off

Five Volt Supply On/Standby

Battery Bus Battery In Use

Buttons:

Upper Alarm Limit

A/D Converter Lower Alarm Limit
Print

On/Off Circuitry On/Standby

Display Board

Figure S4-5: Display Board Block Diagram

The display driver ICs consist of U1, U2, and U3, which use a three-wire
serial interface connect to the CPU (U3) on the UIF module. The three
drivers used on this module are cascaded together and require that the host
processor write 48 bits (16 x 3) to the board per each display update.

The front-panel POWER LED (DS23) is lit whenever the monitor power
supply is on. Note that the drivers do not provide power to light the
BATTERY CHARGING indicator; current for this LED is provided by the
UIF module.

There are four buttons on the display panel: the ON/STANDBY button (SW2)
is connected directly to the UIF module. The other three—UPPER ALARM
LIMIT (SW1), LOWER ALARM LIMIT (SW3), and PRINT (SW4)—are
resistor- weighted and attached via one signal line to an A/D channel of the
UIF module. U4 is a drain device used to guarantee a certain resistance
value when a button is pressed.

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Technical Supplement

The J1 connector pinouts are as follows:

1 +5V power for display drivers 8 NC

2 +5V power for display drivers 9 ON button signal, ONBUTTON
3 +5V power for green LED, GREENPWR 10 Button signal, BUTRES
4 Serial clock to display drivers, SERCLK 11 NC
5 Load data to display drivers, LED1EN 12 NC
6 Serial data to display drivers, SERDATA 13 Ground
7 Current source to battery charging 14 Ground
indicator, CHRGPWR

S.5 SCHEMATIC DIAGRAMS

The following part locator diagrams and schematics are included in this
section:

Figure Description
Figure S5-1 SpO 2 PCB Part Locator Diagram
Figure S5-2 UIF PCB Part Locator Diagram
Figure S5-3 SpO 2 Controller PCB Part Locator Diagram
Figure S5-4 Communications PCB Part Locator Diagram
Figure S5-5 Display PCB Part Locator Diagram
Figure S5-6 SpO 2 Schematic Diagram
Figure S5-7 UIF Schematic Diagram
Figure S5-8 SpO 2 Controller Schematic Diagram
Figure S5-9 Communications Schematic Diagram
Figure S5-10 Display Schematic Diagram
Figure S5-11 Lower Docking Connector Schematic Diagram

S-20