NX2C4X Manual

Networked Four Channel LDT Interface

Overview

The AMCI Nexus LDT Interface module connects a LDT sensor to a network. The available
networks, along with the corresponding AMCI part number are shown in the following table.

Multiple Magnet
LDT Interface
Network LDT Interface
Part Number
Part Number
ControlNet NX2C4C NX2C4C-08
DeviceNet NX2C4D Not Available
Ethernet NX2C4E NX2C4E-08
Profibus NX2C4P Not Available
Modbus TCP/IP NX2C4T NX2C4T-08

The NX2C4X uses twenty-eight 16 bit input words and thirty-three 16 bit output words to
communicate with the network.

The NX2C4X-08 multiple magnet version uses 136 16 bit input words and thirty three 16 bit
output words to communicate with the network.

Note: Because DeviceNet and Profibus do not support the transfer of 136 words; these versions
of the Multiple Magnet LDT Interface Nexus are not available.

Sample programs for this and other AMCI products are available from the following page of our
website.

http://www.amci.com/sampleprograms.asp

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Table of Contents
General Information 3

Installation Chapter 1 4
Hardware Overview 4
Sensor Connector & Wiring 5
LED Function 6
Module Specifications 6
Mounting 8

Programmable Parameters Chapter 2 11

Count Direction 11
Transducer Fault Latch 11
Velocity Update Time 11
LDT Mode 11
Number of Recirculations 11
LED Enable 11
LDT Gradient 12
Full Scale Count 12
Full Scale Length 12
Preset Value 12
Apply Preset 12
EEPROM Use Warning 12

NX2C4X Input & Output Registers Chapter 3 13

Input Words 13
Status Bits 14
Output Words 15
Control Word 16
Configuration Word 16

NX2C4X-08 Input & Output Registers Chapter 4 17

Input Words 17
Status Bits 18
Output Words 19
Control Word 20
Configuration Word 20

General Programming Notes and Chapter 5 21

Programming Sequence

Network Configurations Chapter 6 22

NX2C4C ControlNet 22
NX2C4D DeviceNet 25
NX2C4E Ethernet IP 28
NX2C4P Profibus 30
NX2C4T Modbus TCP/IP 33

Manual Revision History Chapter 6 37

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General Information

Important User Information

The products and application data described in this manual are useful in a variety of different
applications. Therefore, the user and others responsible for applying these products described
herein are responsible for determining the acceptability for each application. While efforts have
been made to provide accurate information within this manual, AMCI assumes no responsibility
for the application or the completeness of the information contained herein. Throughout this
manual the following two notices are used to highlight important points.

WARNINGS tell you when people may be hurt or equipment may be damaged if the procedure
is not followed properly.

CAUTIONS tell you when equipment may be damaged if the procedure is not followed properly.
No patent liability is assumed by AMCI, with respect to use of information, circuits, equipment,
or software described in this manual. The information contained within this manual is subject to
change without notice. UNDER NO CIRCUMSTANCES WILL ADVANCED MICRO
CONTROLS, INC. BE RESPONSIBLE OR LIABLE FOR ANY DAMAGES OR LOSSES,
INCLUDING INDIRECT OR CONSEQUENTIAL DAMAGES OR LOSSES, ARISING FROM
THE USE OF ANY INFORMATION CONTAINED WITHIN THIS MANUAL, OR THE USE
OF ANY PRODUCTS OR SERVICES REFERENCED HEREIN.

Standard Warranty
ADVANCED MICRO CONTROLS, INC. warrants that all equipment manufactured by it will be
free from defects, under normal use, in materials and workmanship for a period of [18] months.
Within this warranty period, AMCI shall, at its option, repair or replace, free of charge, any
equipment covered by this warranty which is returned, shipping charges prepaid, within 18
months from date of invoice, and which upon examination proves to be defective in material or
workmanship and not caused by accident, misuse, neglect, alteration, improper installation or
improper testing. The provisions of the “STANDARD WARRANTY” are the sole obligations of
AMCI and excludes all other warranties expressed or implied. In no event shall AMCI be liable
for incidental or consequential damages or for delay in performance of this warranty.

Returns Policy
All equipment being returned to AMCI for repair or replacement, regardless of warranty status,
must have a Return Merchandise Authorization number issued by AMCI. Call (860) 585-1254
with the model and serial numbers along with a description of the problem. A “RMA” number
will be issued. Equipment must be shipped to AMCI with transportation charges prepaid. Title
and risk of loss or damage remains with the customer until shipment is received by AMCI.

24 Hour Technical Support Number

Technical Support, in the form of documents, FAQs, and sample programs, is available from our
website, www.amci.com. 24 Hour technical support is also available on this product. For
technical support, call (860) 585-1254. Your call will be answered by the factory during regular
business hours, Monday through Friday, 8AM - 5PM EST. During non-business hours, an
automated system will ask you to leave a detailed message and the telephone number that you can
be reached at. The system will page an engineer on call. Please have your product model number
and a description of the problem ready before you call.

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Chapter 1: Hardware Overview

Sensor 1 Sensor 2 Sensor 3 Sensor 4

1234567 1234567 1234567 1234567
Power
Status Power
LDT Status LEDs Connector
1 2 3 4
AMCI 123

RS485 + - GND
24 VDC

Nexus
Digital
Interface

Dimensions
Network Status and Interface
(See the Network installation guides at
Length = 5.75 inches
the end of the specifications)
Width = 4.595 inches
Height = 3.00 inches

Power Connector
Pin Function
1 +24Vdc
2 DC Common
3 Shields

The Nexus Module requires 500 mA of current @24Vdc to operate. If the sensors are being
powered from the Nexus unit, add the power requirements of the sensor to those of the
Nexus.

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Sensor Connectors& Wiring

The Sensor Input Connectors, labeled “SENSOR

1” through “SENSOR 4” have seven contacts. The
mating connectors are supplied with the
NX2C4X. The AMCI part number for the mating Shields
Chassis Ground
connector is MS-7P, while the Phoenix Contact
part number is MC1,5/7-ST-3,81, order number +24Vdc Output
1803620. DC Ground
-Gate or –Start/Stop
+Gate or +Start/Stop
-Interrogation
+Interrogation

The +24Vdc Output pin, (#6), is directly connected to the +24Vdc pin
on the Power connector of the NX2C4X. If your LDT sensor uses
+24Vdc as its power source, then you can use this pin to power the
sensor. DO NOT APPLY +24Vdc TO THIS PIN. Doing so will damage
the NX2C4X and possibly your power supply.

If your sensor uses a different supply voltage, such as +/- 15Vdc,

connect the Common of both the Nexus and the sensor’s power supply
together, and leave the +24Vdc terminal open.

Transducer Cable Installation

Follow the transducer manufacturer’s suggestions when specifying the transducer cable. Pre-
assembled and tested cables are usually offered by the manufacturer. When installing the
transducer cable, follow these general guidelines.

LDT signals are low voltage, low power signals. LDT cables must use shielded cable and can
be installed in conduit along with other low power cabling such as communication cables and
low power ac/dc I/O lines. They cannot be installed in conduit with ac power lines or high
power ac/dc I/O lines. Most factory automation manufacturers offer excellent written
guidelines for cabling installation that you can refer to for additional information..

The shields of the transducer cable must be grounded at one point only! When installing the
cable, treat the shield as a signal carrying conductor and do not connect the shield to ground
at any junction box.

1) If you are making your own transducer cable, ground the shields at the NX2C4X by
connecting them to the Shields pin (#7) of the Sensor Input Connector. Do not connect
the shields to the body of the transducer.
2) If you are using a pre-made cable, or the LDT transducer has an integral cable, verify
that the shields are electrically isolated from the body of the transducer. If they are
connected, then properly ground the body of the transducer and DO NOT connect the
shields to Shields pin (#7) of the Sensor Input Connector. The preferred grounding
connection for the transducers’ shields is at the NX2C4X. Use this point unless the
shields are connected to the body of the transducer through a pre-made or integral
cable. Following this practice will eliminate ground loops that could damage the
transducer or NX2C4X.

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LDT Status LEDs

Function LED Pattern

LDT OK solid green
Clearable Transducer Fault Flashing green
Non Clearable Transducer Fault flashing red
Module Fault solid red

It is possible to enable or disable the LEDs when programming the Nexus module. The
default LED function has only LED 1 enabled.

Module Specifications

Throughput Time
The throughput time of the Nexus LDT Interface is dependent on the type of unit and how its
parameters are configured and represents how long the module will need to decode the position
data. It does not include the time that it will take to transfer data to and from the Nexus module
over the network.

NX2C4X: 2ms minimum. Maximum time dependent on the value of the length parameter
and the location of the magnet on the sensor
NX2C4X-08: The update time is either 2ms or the result of (Length * 40 * 1.3) whichever
is greater. The result of this calculation is in µs.

Data I/O Words

NX2C4X: 28 input and 33 output words
NX2C4X-08: 136 input and 33 output words

Compatible Transducers
Sensors manufactured by Balluff, MTS, Ametek, and Turck
Above brands with start - stop or PWM (with External Interrogation) digital outputs

Number of Transducer Inputs

Four

Transducer Input Isolation

Optically Isolated (1,500 Vac)

Programmable Parameters
Count Direction
Transducer Fault Latch (Latched or Self Clearing)
Velocity Update Time (160ms or 24ms)
LDT Mode (Start/Stop or PWM)
Number of Recirculations (one or four)
Enable / Disable Channel LED
LDT Gradient
Full Scale Count
Full Scale Length
Preset Value

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Data Value (position) Range

±268,435,455 counts max.

Data Value (position) Preset

Data Value can be preset to any value within the position range.

Rate of Change (velocity) Range

±268,435,455 counts per second max.

Program Memory
EEPROM. Rated for 100,000 write cycles

Data Available to Network

Data Value, Rate of Change, status bits.

NX2C4X Mounting
DIN rail or panel mount. Kit included with unit that allows customer to change mounting styles.
DIN channel, not supplied with the NX2C4X, can be EN 50 002 or EN 50 035.

Environmental Conditions
Operating Temperature: 0 to 60°C
Relative Humidity 5 to 95% (without condensation)
Storage Temperature: -40 to 85°C

NEMA Rating
NEMA 1. Must be mounted in a suitable enclosure to protect it from airborne and liquid
contaminates.

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Mounting the NX2C4X

The next two pages show the NX2C4X in its DIN rail and panel mount configurations. The
mounting kit, included with the unit, contains two DIN brackets, two panel brackets, and four #8
screws needed to attach your choice of brackets to the NX2C4X. Note that the unit is not sealed
and the NX2C4X must be installed in an adequate enclosure to protect it from environmental
contaminates.

DIN Rail Mounting

As shown in the following figure, the unit can be DIN rail mounted in two ways. The brackets
accept EN 50 002 or EN 50 035 channel. Note that DIN channel is not included with the
NX2C4X.

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Panel Mounting
As shown in the figure below, the NX2C4X can be panel mounted in two ways. The mounting
kit, included with the unit, contains the two panel brackets and four #8 screws needed to attach
the brackets. The slots in the brackets for mounting the unit to the panel are made to accept #8
screws or bolts. The lengths of these screws or bolts depends on your application, and are not
included with the unit.

Panel Mounting Brackets, Rear Mount Position.

Panel Mounting Brackets, Foot Mount Position.

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Mounting

The NX2C4X can be panel mounted in two ways, either on a DIN rail or panel mounted. The
mounting kit, included with the unit, contains two DIN brackets, two panel brackets, and four #8
screws needed to attach your choice of brackets to the NX2C4X. Note that the enclosure is not
sealed and the NX2C4X must be installed in an adequate enclosure to protect it from
environmental contaminates.

Attaching the DIN Brackets

The following figure shows how to install the DIN brackets so that the NX2C4X can be mounted
on EN 50 022 or EN 50 035 rail. Note that the bottom view of the unit is shown. The rear view is
similar and the brackets are installed in the same fashion.

Attaching the Panel Brackets

The following figure shows how to install the panel brackets so that the NX2C4X can be securely
mounted to an enclosure. Note that the bottom view of the unit is shown. The rear view is similar
and the brackets are installed in the same fashion.

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Chapter 2: Programmable Parameters

The NX2C4X is configured by programming its Programmable Parameters. These parameters
are sent to the NX2C4X using the output registers assigned to it on the network.

Count Direction: This parameter gives you the ability to reverse the direction of motion needed
to increase the position count. For simplicity’s sake, the two values for this parameter are called
Positive Direction and Negative Direction. When this parameter is set to its default of Positive,
the Data Value is not changed. When this parameter is set to Negative, the Data Value is
multiplied by -1 before it is reported. For linear transducers, this has the effect of reversing the
direction of motion needed to increase the count. When using LDT’s and the Count Direction is
set to Positive, the Data Value usually increases as the magnet moves away from the head of the
LDT. When the Count Direction is set to Negative, the Data Value increases as the magnet moves
towards the head of the LDT. You will need probably need to Apply the Preset to the Data Value
after you program the Count Direction parameter.

Transducer Fault Latch - Transducer faults can be caused by improper wiring, electrical noise,
or a damaged transducer. When the unit detects a fault condition, it reports this fault over the
backplane. Normally, a transducer fault is not latched by the NX2C4X module and the
Transducer Fault conditions will be cleared as soon as the NX2C4X module detects valid LDT
signals. If you have a situation where electrical noise is causing spurious transducer faults that
you can safely ignore, leave this parameter in its default condition. However, if you want to
reliably capture these transient faults, then you must enable the Transducer Fault Latch
parameter. In this case, you must send a Clear Error command to the NX2C4X module to clear
the fault. The default Transducer Fault Latch value is set to Self Clearing.

Velocity Update Time: The Velocity Update Time parameter sets the amount of time between
Rate of Change information updates to the PLC. Its can be set to either 160 milliseconds or 24
milliseconds, with 160 milliseconds being the default. Decrease the time between updates for
faster response to changes in this value. Increase the time between updates for better averaging of
this value. The Velocity update time does not affect the rate at which the position data is
updated.

The Velocity data is measured in Counts/Second. For example, if you have programmed the
NX2C4X module for 0.001 inch resolution, and if the magnet is moving at a rate of two inches
per second, then the NX2C4X module will report a velocity value of 2000 counts / second.

LDT Mode – A Configuration Word bit is used to select the desired LDT mode, which can be
one of the two following modes.
• Start/Stop Mode (default)
• PWM Mode (external interrogation only, with either 1 or 4 recirculations)

Number of Recirculations: This bit level parameter controls how many times the NX2C4X will
interrogate the sensor before reporting the position data to the network. For correct readings, this
parameter must match the number of recirculations expected by PWM sensors.

LED Enable: This parameter gives you the ability to enable or disable the Unit Status LED of
the corresponding Sensor Input Channel. When disabled, the LED is always off and does not
show the status of the NX2C4X. The channel will continue to function, regardless of the state of
the LED.

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LDT Gradient (Wire Speed) - This is a calibration parameter supplied by the LDT manufacturer
and defines how fast the pulse travels down the waveguide of the sensor. The data reported by
the NX2C4X module will be repeatable, but not accurate, if an incorrect Gradient value is used.

LDT manufacturers specify the gradient in µSec/inch, µsec/mm, or meters/second.

The gradient value used by the NX2C4X module has a range of 80000 to 99999, a default value
of 90000 (for 9.0000 µsec/inch) and is always programmed in µsec/inch. Use the following
formulas to convert from µsec/mm or meters/second to µsec/inch.

Gradient in µsec/inch = (Gradient in µsec/mm * 25.4 mm/inch)

Gradient in µsec/inch = 1 / (Gradient in meters/sec * 0.00003937)

Full Scale Length - Most commonly set to the expected length of travel, the Full Scale Length
can actually be any value that simplifies the Full Scale Count value. The range of values is 2 to
800 inches. Default value of 40.

Full Scale Count - Sets the number of counts over the specified Full Scale Length. The range of
values is 2 to (Full Scale Length * 1000) Default value of 40,000.

Preset Value: The zero position of the LDT encoder’s Data Value may not match the zero
position of the application machine. The Preset Value parameter gives you the ability to offset
the Data Value from the actual LDT data to a value that will be more useful for your application.

Programming the Preset Value parameter does not change the Data Value. It is stored in
the NX2C4X module’s memory until the module sees the Apply Preset bit set during a
programming cycle.

Apply Preset: Offsetting the Data Value to the Preset Value is a two step operation. First, the
Preset Value is programmed with the other setup parameters. Second, setting the Apply Preset bit
in the output registers will change the Data Value to the Preset Value. These two operations
cannot be performed during the same programming cycle.

Setting the Apply Preset bit causes the module to generate an internal offset value that is
applied to the Data Value before it is reported to the PLC. This internal offset is saved in
the NX2C4X module’s memory, so it is not necessary to home the module at every power
up. Please note that programming a channel’s setup data will clear the internal offset
generated by an Apply Preset operation.

The NX2C4X module’s EEPROM memory is guaranteed for 100,000 write

cycles before writing to it will cause it to fault. Therefore continuously
applying the Preset should be avoided. If your application requires you to
continuously apply the Preset, consider calculating and applying the Preset
in your PLC program.

The Nexus LDT measures only in units of inches. However, the Full
Scale Length and Full Scale Count parameters can be used to scale the
position data so that it is reported in millimeters. To accomplish this, set
the Length to its inch value and the Full Scale Count to (254 * Length in
inches). The resolution will be 0.1mm.

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Chapter 3: Single Magnet LDT Interface NX2C4X

(28 Input Words and 33 Output Words)

The single magnet Digital Interface can interface with sensors that have either Start/Stop or Pulse
Width Modulated outputs.

Because the data from the Nexus LDT interface module may be
updated asynchronously to the program scan, AMCI
recommends that the input data be buffered by copying it into
internal registers before it is used by the ladder logic program.

Input Words for LDT with Recirculations or Pulse Width Modulation

Channel Word # LDT Parameter Units

0 Channel 1 Status
1 Channel 1 upper 4 digits position Scaled
1 2 Channel 1 lower 4 digits position Counts
3 Channel 1 upper 4 digits velocity Counts /
4 Channel 1 lower 4 digits velocity Second
5 Channel 2 Status
6 Channel 2 upper 4 digits position Scaled
2 7 Channel 2 lower 4 digits position Counts
8 Channel 2 upper 4 digits velocity Counts /
9 Channel 2 lower 4 digits velocity Second
10 Channel 3 Status
11 Channel 3 upper 4 digits position Scaled
3 12 Channel 3 lower 4 digits position Counts
13 Channel 3 upper 4 digits velocity Counts /
14 Channel 3 lower 4 digits velocity Second
15 Channel 4 Status
16 Channel 4 upper 4 digits position Scaled
4 17 Channel 4 lower 4 digits position Counts
18 Channel 4 upper 4 digits velocity Counts /
19 Channel 4 lower 4 digits velocity Second
20 0
21 0
22 0
23 0
24 0
25 0
26 0
27 0

Note 1: A NX2C4P unit will require that you configure your scanner for all twenty-eight 16 bit
input words.
Note 2: To reduce the amount of data transferred, the number of input words can be reduced to
20 for an Ethernet IP system, and 22 for a ControlLogix system.
Note 3: A ControlLogix system using ControlNet will require 22 input words. The first two
words will always be zero, and the Channel 1 Status Word will be located in word 2.
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NX2C4X Status Word Layout

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Configuration error (bit 0)
Gradient Error (bit 1)

Length Error (bit 2)

Full Scale Count Error (bit 3)

Position Preset Error (bit 4)

Command Error (bit 6)

Message Ignored (bit 7)

Velocity at 0 bit (bit 8)
Motion Direction (bit 9)
0=increasing 1 = decreasing
Position Value Sign (bit 10)
0=positive 1= negative
Velocity Overflow (bit 12)
LDT Fault (bit 13)
Module Error (bit 14)
ACK (bit 15) (channel 1only)

Configuration Error: Set if any of the unused bits in the configuration word are set
Gradient Error: This bit is set if the Gradient Value is outside the expected range
80000...99999, or if the lower gradient word exceeds 9999.
Length Error: Full Scale Length is outside the expected range (2 to 800)
Full Scale Count Error: Set if the Full Scale Count is outside the range of (2 to (Length * 1000))
Position Preset Error: Set if the preset value is outside of the range of +268,435,455
Command Error: Set if any of unused bits in the command word are set, or if both the
Program Channel and Apply Preset bits are set during the same
programming sequence.
Message Ignored: Set if an attempt is made to program a parameter if an error already exits
on a different parameter, or if an attempt is made to apply the preset
value to a channel that is faulted. This bit is not set if the same channel
is programmed a second time with incorrect data.
Motion Direction: This bit will be “0” if the position is increasing, or “1” if the position is
decreasing. The bit will remain in its last state when there is no motion.
Position Value Sign: This bit will be “0” if the position is positive, or “1” if the position is
negative.
Velocity at Zero: This bit will be set if there has been no motion for the last portion of the
Velocity Update Time.
Velocity Overflow: This bit will be set if the rate of change value exceeds 2^32 counts per
second. When this occurs, the last valid value is sent to the processor.
LDT Fault: This bit will be set if a transducer fault has been detected caused by
improper programming, improper installation or faulty transducer.
Module Fault: Set on EEPROM or PLD fault.
Acknowledge Bit: Set when the transmit bit is set. This bit is present only in the channel 1
status data.

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NX2C4X Output Words

Channel Word LDT Set Up Word Range
All 0 Control See Below
1 Channel 1: Configuration See Below
2 Channel 1: Upper 1 Digit Gradient 80,000 to
3 Channel 1: Lower 4 Digits Gradient 99,999
4 Channel 1: Upper 2 Digits Full Scale Count 2 to (Full Scale
1
5 Channel 1: Lower 4 Digits Full Scale Count Length * 1000)
6 Channel 1: Full Scale Length 2 to 800
7 Channel 1: Upper 4 Digits Preset Value +sign
+268,435,455
8 Channel 1: Lower 4 Digits Preset Value
9 Channel 2: Configuration See Below
10 Channel 2: Upper 1 Digit Gradient 80,000 to
11 Channel 2: Lower 4 Digits Gradient 99,999
12 Channel 2: Upper 2 Digits Full Scale Count 2 to (Full Scale
2
13 Channel 2: Lower 4 Digits Full Scale Count Length * 1000)
14 Channel 2: Full Scale Length 2 to 800
15 Channel 2: Upper 4 Digits Preset Value + sign
+268,435,455
16 Channel 2: Lower 4 Digits Preset Value
17 Channel 3: Configuration See Below
18 Channel 3: Upper 1 Digit Gradient 80,000 to
19 Channel 3: Lower 4 Digits Gradient 99,999
20 Channel 3: Upper 2 Digits Full Scale Count 2 to (Full Scale
3
21 Channel 3: Lower 4 Digits Full Scale Count Length * 1000)
22 Channel 3: Full Scale Length 2 to 800
23 Channel 3: Upper 4 Digits Preset Value + sign
+268,435,455
24 Channel 3: Lower 4 Digits Preset Value
25 Channel 4: Configuration See Below
26 Channel 4: Upper 1 Digit Gradient 80,000 to
27 Channel 4: Lower 4 Digits Gradient 99,999
28 Channel 4: Upper 2 Digits Full Scale Count 2 to (Full Scale
4
29 Channel 4: Lower 4 Digits Full Scale Count Length * 1000)
30 Channel 4: Full Scale Length 2 to 800
31 Channel 4: Upper 4 Digits Preset Value + sign
+268,435,455
32 Channel 4: Lower 4 Digits Preset Value

1. The Gradient, Full Scale Count, and Preset Value parameters are divided into two words.
The upper word contains the 10,000 and above places, the lower word contains the 1s, 10s,
100s, and 1000s places. For example, if your Full Scale Count value is 16,500, then the
upper word would be equal to “1” and the lower word would be equal to “6500.”
2. The preset value has a range of +268,435,455 and a default of zero. Negative Preset values
are transmitted with bit 15 set in the upper word of the corresponding Preset Value.
3. The Nexus LDT measures only in inches. However, the Full Scale Length and Full Scale
Count parameters can be used to scale the position data so that it is reported in millimeters.
To accomplish this, set the Length to its inch value and the Full Scale Count to (254 * Length
in inches). The resolution will be 0.1mm.

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NX2C4X Control Word Layout

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

Apply Preset channel 1 (bit 0)

Apply Preset channel 2 (bit 1)
Apply Preset channel 3 (bit 2)
Apply Preset channel 4 (bit 3)

Program channel 1 (bit 4)

Program channel 2 (bit 5)
Program channel 3 (bit 6)
Program channel 4 (bit 7)

Clear Errors (bit 14)

Transmit Bit (bit 15)
Note: A Command Error is generated if you try to both preset and program a channel in a single
programming sequence. However, it is possible to program a channel while presetting a
different channel.

NX2C4X Configuration Word Layout

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Count Increase for Travel (bit 0)
(0 = Same Direction)
Transducer Fault Latch (bit 1)
(0 = latching, 1 = self clearing)
Velocity Update Time (bit 2)
(0=160mS, 1=24mS)
LDT Mode (bit 3)
(0 = Start/Stop, 1 = PWM)
Using Recirculations (bit 4)
(1 = 4 Recirculations)
Enable LED (bit 13) 0=disable

1. The Configuration Word has a default value of 0.

2. All bits that are not used, 5 to 12, 14, and 15, must be reset to zero or a configuration error
will be generated.
3. Changing the direction of increasing counts sets the position sign bit in the input register’s
status data. The absolute value of the position data is not affected.
4. Changing the sensor type from RPM to DPM or vice versa will cause the Nexus unit to
indicate a clearable transducer fault, unless the unit has also been configured to self clear the
transducer fault.
5. The position update time is dependent on the programmed length parameter and an internal
calculation. If the result of multiplying the (Length * 40 * 1.3µs) is less than 2ms, then the
position is updated every 2ms. However, if the result of this calculation is greater than 2ms,
than the result of this calculation is used for the position update time.

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Chapter 4: Multiple Magnet LDT Interface NX2C4X-08

(136 Input Words and 33 Output Words)
(A maximum of 16 magnets can be used on each sensor)

Because the data from the Nexus LDT interface module may be
updated asynchronously to the program scan, AMCI
recommends that the input data be buffered by copying it into
internal registers before it is used by the ladder logic program.
Input Words for LDT with Multiple Magnets

Word # LDT Parameter

0 Channel 1, Status
Note: A ControlLogix system 1 Channel 1, Position Signs Word
using ControlNet will require
2 Channel 1, Magnet 1 upper 4 digits position
138 input words. The first two
words will always be zero, and 3 Channel 1, Magnet 1 lower 4 digits position
the Channel 1 Status Word will 4 Channel 1, Magnet 2 upper 4 digits position
be located in word 2. 5 Channel 1, Magnet 2 lower 4 digits position
6 to 33 Channel 1, Magnet 3 ... 16 position
34 Channel 2, Status
35 Channel 2, Position Signs Word
36 Channel 2, Magnet 1 upper 4 digits position
37 Channel 2, Magnet 1 lower 4 digits position
38 to 67 Channel 2, Magnet 2 ... 16 position
68 Channel 3, Status
69 Channel 3, Position Signs Word
70 Channel 3, Magnet 1 upper 4 digits position
71 Channel 3, Magnet 1 lower 4 digits position
72 to 101 Channel 3, Magnet 2 ... 16 position
102 Channel 4, Status
103 Channel 4, Position Signs Word
104 Channel 4, Magnet 1 upper 4 digits position
105 Channel 4, Magnet 1 lower 4 digits position
106 to 135 Channel 4, Magnet 2 ... 16 position

Note 1: The position sign words are used to indicate the sign of each of the 16 magnets in the
channel. If the bit is reset, “0”, the position is positive, if the bit is set, “1”, the
position is negative. Bit 0 = magnet 1 position sign, bit 1 = magnet 2 position sign,
… bit 15 = magnet 16 position sign.

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NX2C4X-08 Status Word

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Configuration error (bit 0)
Gradient Error (bit 1)

Length Error (bit 2)

Full Scale Count Error (bit 3)

Position Preset Error (bit 4)

Command Error (bit 6)

Message Ignored (bit 7)
LDT Fault (bit 13)
Module Error (bit 14)
ACK (bit 15) (channel 1only)

Configuration Error: Set if any of the unused bits in the configuration word are set, if the
length parameter is not twice the number of magnets, or if the channel is
configured to operate with a DPM sensor and more than one magnet.
Gradient Error: This bit is set if the Gradient Value is outside the expected range
80000...99999, or if the lower gradient word exceeds 9999.
Length Error: Full Scale Length is outside the expected range (2 to 800)
Full Scale Count Error: Set if the Full Scale Count is outside the range of (2 to (Length * 1000))
Position Preset Error: Set if the preset value is outside of the range of +268,435,455
Command Error: Set if any of unused bits in the command word are set, or if both the
Program Channel and Apply Preset bits are set during the same
programming sequence.
Message Ignored: Set if an attempt is made to program a parameter if an error already exits
on a different parameter, or if an attempt is made to apply the preset
value to a channel that is faulted. This bit is not set if the same channel
is programmed a second time with incorrect data.
LDT Fault: This bit will be set if a transducer fault has been detected caused by
improper programming, improper installation or faulty transducer. This
bit will also be set if the unit has been programmed for more magnets
than are present on the sensor.
Module Fault: Set on EEPROM or PLD fault.
Acknowledge Bit: Set when the transmit bit is set. This bit is present only in the channel 1
status data.

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NX2C4X-08 Output Words

Channel Word LDT Set Up Word Range
All 0 Control See Below
1 Channel 1: Configuration See Below
2 Channel 1: Upper 1 Digit Gradient 80,000 to
3 Channel 1: Lower 4 Digits Gradient 99,999
4 Channel 1: Upper 2 Digits Full Scale Count 2 to (Full Scale
1
5 Channel 1: Lower 4 Digits Full Scale Count Length * 1000
6 Channel 1: Full Scale Length 2 to 800
7 Channel 1: Upper 4 Digits Preset Value +sign
+268,435,455
8 Channel 1: Lower 4 Digits Preset Value
9 Channel 2: Configuration See Below
10 Channel 2: Upper 1 Digit Gradient 80,000 to
11 Channel 2: Lower 4 Digits Gradient 99,999
12 Channel 2: Upper 2 Digits Full Scale Count 2 to (Full Scale
2
13 Channel 2: Lower 4 Digits Full Scale Count Length * 1000
14 Channel 2: Full Scale Length 2 to 800
15 Channel 2: Upper 4 Digits Preset Value + sign
+268,435,455
16 Channel 2: Lower 4 Digits Preset Value
17 Channel 3: Configuration See Below
18 Channel 3: Upper 1 Digit Gradient 80,000 to
19 Channel 3: Lower 4 Digits Gradient 99,999
20 Channel 3: Upper 2 Digits Full Scale Count 2 to (Full Scale
3
21 Channel 3: Lower 4 Digits Full Scale Count Length * 1000
22 Channel 3: Full Scale Length 2 to 800
23 Channel 3: Upper 4 Digits Preset Value + sign
+268,435,455
24 Channel 3: Lower 4 Digits Preset Value
25 Channel 4: Configuration See Below
26 Channel 4: Upper 1 Digit Gradient 80,000 to
27 Channel 4: Lower 4 Digits Gradient 99,999
28 Channel 4: Upper 2 Digits Full Scale Count 2 to (Full Scale
4
29 Channel 4: Lower 4 Digits Full Scale Count Length * 1000
30 Channel 4: Full Scale Length 2 to 800
31 Channel 4: Upper 4 Digits Preset Value + sign
+268,435,455
32 Channel 4: Lower 4 Digits Preset Value

1. The Gradient, Full Scale Count, and Preset Value parameters are divided into two words.
The upper word contains the 10,000 and above places, the lower word contains the 1s,
10s, 100s, and 1000s places. For example, if your Full Scale Count value is 16,500, then
the upper word would be equal to “1” and the lower word would be equal to “6500.”
2. The preset value has a range of +268,435,455 and a default of zero. Negative Preset are
transmitted with bit 15 set in the upper word of the corresponding Preset Value.
3. The Nexus LDT measures only in inches. However, the Full Scale Length and Full Scale
Count parameters can be used to scale the position data so that it is reported in
millimeters. To accomplish this, set the Length to its inch value and the Full Scale Count
to (254 * Length in inches). The resolution will be 0.1mm.

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NX2C4X-08 Control Word Layout

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

Apply Preset channel 1 (bit 0)

Apply Preset channel 2 (bit 1)
Apply Preset channel 3 (bit 2)
Apply Preset channel 4 (bit 3)

Program channel 1 (bit 4)

Program channel 2 (bit 5)
Program channel 3 (bit 6)
Program channel 4 (bit 7)

Clear Errors (bit 14)

Transmit Bit (bit 15)

1. A Command Error is generated if you try to both preset and program a channel in a single
programming sequence. However, it is possible to program a channel while presetting a
different channel.
2. Applying the Preset to an LDT with Multiple Magnets sets the position for the first magnet
to the programmed preset value. The offset that was necessary to set the first magnet to the
preset value is also applied to the remaining magnets, maintaining the distance between
each of the magnets.

NX2C4X-08 Configuration Word Layout

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Count Increase for Travel (bit 0)
(0 = Same Direction)
Transducer Fault Latch (bit 1)
(0 = latching, 1 = self clearing)

LDT Mode (bit 3)

(0=Start / Stop)
(1 = using PWM,1 magnet only)

Bits 8 to 12 program the number of

magnets, 1 to 16

Enable LED (bit 13)

1 = enabled 0 = disabled
1. The Configuration Word has a default value of 0.
2. Bits 2, 4 to 7, 14, and 15 must be reset or a configuration error will be generated.
3. Bits 8 through 12 set the number of magnets in use. The range is 1 to 16. Entering a
value of zero will generate a configuration error.
4. The length parameter must be at least twice the number of magnets, or a configuration
error will be generated.
5. An LDT error will be reported if the unit has been programmed for more magnets than
are present on the sensor. However, the module will operate correctly if the number of
magnets on the sensor exceeds the value programmed.

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6. The module can only be configured to accept signals from a sensor with a Digital
Personality module if the number of magnets is set to 1. If the number of magnets is
greater than 1, programming the module for a DPM sensor will cause a configuration
error to be generated.
7. It is not possible to program the multiple magnet module for more than one recirculation.
8. Multiple magnets should kept at least three inches from each other. If the magnets are
moved together closer than this, the position data of the magnet farther from the head of
the sensor will increase. If the magnets are moved closer together still, the return signal
from the farther magnet will disappear, and the unit will go into transducer fault.
9. The update time is either 2ms or the result of (Length * 40 * 1.3) whichever is greater.
The result of this calculation is in µs.

Chapter 5 General Programming Notes and Programming

Sequence
General Programming Notes

1. It is possible to enable or disable the four status LEDs. The channels are always are enabled,
and will function normally, even if the LED is disabled. By default, only the channel 1 LED
is enabled.
2. It is possible to program multiple channels at one time.
3. When programming a channel, all of the data must be correct before it will be acted upon.
However, if the data on one channel is incorrect, and the data on another channel is correct,
than the data from the correct data will be accepted even if the channel with the incorrect data
comes first.
4. If a programming error exists on any of the channels, the error must be cleared before a
different channel can be programmed.
5. It is not possible to program and apply the preset value with one programming sequence.
However, it is possible to program one channel and apply the preset to another channel.
6. Balluff recommends that only their magnets be used on their transducers.
7. Default parameters are loaded with jumper strap installed on JP3 at power up.
8. The Gradient, Full Scale Count, and Preset Value parameters, as well as the input position
and velocity data, are divided into two words. The upper word contains the 10,000 and above
places, the lower word contains the 1s, 10s, 100s, and 1000s places. For example, if your
Full Scale Count value is 16,500, then the upper word would be equal to “1” and the lower
word would be equal to “6500.”

To combine the position or velocity data into one 32 bit register, multiply the upper word by
10000 and add the lower word to it.

Programming Sequence

1. The ladder logic program writes the data into the output registers.
2. The ladder logic program then sets the transmit bit.
3. When the module detects the 0 to 1 transition of the transmit bit, it will respond by setting
any error bits and the Acknowledge bit in the input registers.
4. When the ladder logic program sees that the Acknowledge bit is set, it will examine any error
bits, and then reset the transmit bit.
5. The module will reset the Acknowledge bit.
6. The programming sequence is now complete.

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Networked Four Channel LDT Interface

Chapter 6: Network Connections

NX2C4C ControlNet Hardware Overview

Note: A ControlLogix system using ControlNet will require 22 input words for the NX2C4C and
138 input words for the NX2C4C-08. The first two words will always be zero, and the
Channel 1 Status Word will be located in word 2.

Sensor 1 Sensor 2 Sensor 3 Sensor 4

1234567 1234567 1234567 1234567
Power
Status Power
LDT Status LEDs Connector
1 2 3 4
AMCI 123

RS485 + - GND
24 VDC

1 3 Nexus
2 4 Digital
1 2 B A Interface
B1 22

Control Net Selects Node Control Net Connectors

Status LEDs Address

ControlNet Connectors

The Nexus module has two BNC network connections labeled A and B. Either can be used,
depending on how the network configuration.

Node Address Selection

The Nexus module has two rotary switches used to set the module’s address on the network.
Any node from 0 to 99 can be selected. Switch 1 sets the one digit and switch 2 sets the 10s
digit of the address. For example, if the Nexus is to be installed at node 46, switch 1 would
be set to 6, and switch 2 would be set to 4. Note, changing the node address only takes
affect at power up. Changing the address while power is applied to the Nexus module will
generate a minor fault.

Network Update Time

The Nexus LDT Interface has a minimum network update time of 5ms.

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ControlNet Status LEDs

The following table describes the function of the four network status LEDs.

LED Name LED Pattern Function

Number
1 Channel Solid Green Channel Operating Correctly
B status Flashing Red/Off Channel Disconnected from Network
Solid Off Channel Disabled
2 Channel Solid Green Channel Operating Correctly
A status Flashing Red/Off Channel Disconnected from Network
Solid Off Channel Disabled
3 Module Solid Green Network Card is communicating with Nexus
Owned Off Network Card is not communicating with Nexus
Solid Red Incorrectly Configured Network. Possible causes
are incorrect Node #, Number of I/O
words, or Comm format.
4 Module Flashing Green Network Card is waiting for initialization
Status Solid Green Module is initialized and operating correctly
Flashing Red Minor Fault (For example Node address changed)
Solid Red Major Fault, module must be restarted

Note: If the Nexus module is removed from the Network, than both LEDs 1 and 2 will flash RED.

Quick Start Guide

AMCI Nexus to ControlLogix
1. With the power off, use the rotary switches on the Nexus to select the desired node address.
2. Connect the Nexus to the ControlNet using a ControlNet Tap to coax media. Either the A or
B port can be used, depending on how your network is configured.
3. Apply power to the Nexus unit.
4. Start RSLogix 5000.
5. Start RSLinx and establish communications to the ControlLogix system.
6. Configure the ControlLogix hardware system, processor and discrete I/O. If it is not already
present, also add the ControlNet adapter 1756-CNB(R) module to the system.
7. Right-click on the 1756-CNB(R) module and Click on New Module…
8. Define the Nexus LDT Interface as a generic CONTROLNET-MODULE. Click on OK and
define the properties as follows.

Name: Your Choice

Description: Your Choice
Comm Format: Data-INT (must be Data-INT)
Node: Set it to the same value as the Node address on the Nexus Digital
Interface
Assembly Instance – 100, Input – 22 for the NX2C4C
138 for the NX2C4C-08
Assembly Instance – 150, Output – 33 for the NX2C4C
33 for the NX2C4C-08
Assembly Instance – 110, Config – 0 for all versions of the Nexus LDT Interface

9. Click on Next>
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Networked Four Channel LDT Interface

10. Define the RPI. The minimum value is 5.0ms, however the value may be set higher.
11. Click Finish.
12. Save and Download the file to the Processor
13. Start RSNetworx for ControlNet and either open an existing project or create a new one.
14. If this is the first time using the Nexus LDT Interface, register the NX2C4C_R01.eds or the
NX2C4C-08_R01.eds EDS and icon files. These files are available from the driver file
section of AMCI’s website www.AMCI.com.
15. Go Online. RSNetWorx will scan the ControlNet network and should discover the Digital
Interface module that you are using.
16. Click on the Enable Edits checkbox and then save the project.

At this point, the 1756-CNB(R) should be communicating; steady green LED and the top right
LED (ControlNet Status LED #3) for the NEXUS communication should be on.

Go online to the ControlLogix processor. Select the Logic menu, followed by Monitor Tags.
The data associated with the Nexus LDT Interface is available under the name you chose when
configuring it.

Quick Start Guide

AMCI Nexus to PLC-5
1. With the power off, use the rotary switches on the Nexus to select the desired node address.
2. Connect the Nexus to the ControlNet using a ControlNet Tap to coax media. Either the A or
B port can be used, depending on how your network is configured.
3. Apply power to the Nexus unit.
17. Start RSNetworx. If this is the first time using the Nexus LDT Interface, register the
NX2C4C_R01.eds or the NX2C4C-08_R01.eds EDS and icon files. These files are
available from the driver file section of AMCI’s website www.AMCI.com.
4. From RSNetworx for ControlNet, go Online. After browsing the network, the Digital
Interface will appear as an “Extra Device” at the node selected by the Nexus’ rotary switches.
5. Click the Enable Edits checkbox and choose “Use online data (upload)”. Click OK. At this
point you can right click on the Nexus LDT Interface icon and select Properties from the
pop-up menu. In the properties window, you can change the name associated with the unit
and add a description.
6. Go Offline.
7. Click the Enable Edits checkbox.
8. Right Click on the PLC-5 icon and click on Scanlist Configuration in the pop-up menu.
9. In the Device Name column, right click on the name of the Nexus unit, and click on Insert
Connection in the pop-up menu. The Connection Properties window will appear on the
screen.
10. If needed, set the Input Size and Input Address of the Data Input File. This file resides in the
PLC-5 and is used by all of the ControlNet nodes. Therefore, it must be large enough to hold
all of the input data on the network. The maximum number of words that the two versions of
the Nexus LDT Interface transfer to the PLC is shown below.

20 Input words for the NX2C4C

136 Input words for the NX2C4C-08

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11. If needed, set the Output Size and Output Address of the Data Output File. This file resides
in the PLC-5 and is used by all of the ControlNet Nodes. Therefore, it must be large enough
to hold all of the output data on the network. The maximum number of words that the two
versions of the Nexus LDT Interface receive from the PLC-5 is shown below.

33 Output words for the NX2C4C

33 Output words for the NX2C4C-08

12. Set the Request Packet Interval time. This has a minimum acceptable value of five
milliseconds, but can be set higher.
13. Click OK to close the Connection Properties window. In the Scanlist Configuration window,
save the changes and close the window.
14. Go Online.
15. Verify that the PLC is in Program Mode.
16. Click on Network in the toolbar select Download to Network from the pull down menu that
appears. After the download is complete, the Nexus unit should be communicating with the
PLC.

NX2C4D DeviceNet Hardware Overview

Because DeviceNet does not support the transfer of 136 output words, a DeviceNet version of the
Multiple Magnet Nexus unit, the NX2C4D-08, does not exist.

Sensor 1 Sensor 2 Sensor 3 Sensor 4

1234567 1234567 1234567 1234567
Power
Status Power
LDT Status LEDs Connector
1 2 3 4
AMCI 123

RS485 + - GND
24 VDC

1 3 Nexus
12345
2 4 Digital
Interface

Network Switches for Node Switch 1

Status LEDs Address and Baud DeviceNet
Rate Connector

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DeviceNet Connector

The 5 pin DeviceNet Connector has the following wiring.

Pin Number Function Standard Wire Color

1 +24Vdc Red
2 Can High White
3 Shields Bare
4 Can Low Blue
5 Common Black
Node Address and Baud Rate Selection

The NX2C4D uses eight DIP switches to select the Node Address and the Baud Rate.
Switches 1 and 2 set the Baud rate and switches 3 to 8 set the node, with switch 8 being the
least significant bit. The following table shows the possible switch setting combinations.

The DIP switch package is mounted so that the numbers are upside down. However, “1” or
“ON” is still in the up position and “0” or “OFF” is in the down position.

Baud Rate Switches 1 & 2 Node Address Switches 3 to 8

125k 00 0 000000
250k 01 1 000001
500k 10 2 000010
Reserved 11 61 111101
62 111110
63 111111

Example: For a Baud Rate = 250K and the Node Address = 5, switches 2, 6, and 8 would be
ON, up towards the top of the module and switches 2, 3, 4, 5, and 7 would be
OFF, down towards the bottom of the module.

Note: The state of the switch settings is only taken into account at power up.

DeviceNet Status LEDs

The following table describes the function of the four network status LEDs.

LED Name LED Pattern Description

Number
1 Module Steady Off No Power
Network Steady Red Unrecoverable Fault
Status Steady Green Device Operational
Flashing Red Minor Fault
2 Network Steady Off Not Powered / Not On Line
Status Steady Red Critical link failure
Steady Green Link OK, On Line, Connected
Flashing Red Connection Time Out
Flashing Green On Line not connected
3 Reserved
4 Reserved

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Adding the NX2C4D to your network

Before the NX2C4D can be attached to a network, it must be added to the RSNetWorx for
DeviceNet software. The EDS and icon files are available in the Driver File Download section of
our website, www.amci.com. The following procedure to add the EDS file to RSNetWorx
assumes that you have already downloaded these files and un-zipped them.

1. With the power off, use the dip switches on the front of the NX2C4D to set the node address
and the baud rate.
2. Start RSNetWorx for DeviceNet.
3. In the RSNetWorx program, click on Tools in the menu bar.
4. Click on EDS Wizard… from the pull down menu that appears.
5. Click on Next> in the window that appears.
6. Select Register an EDS file(s) and click on Next>.
7. Select Register and EDS file.
8. Click on Choose File… and navigate to the folder where you placed the un-zipped EDS and
icon files.
9. Double click on NX2C4D_r01.eds file.
10. Click on Next>.
11. Click on NX2C4D_r01.eds file so that it is highlighted.
12. Click on Next> to assign an icon to the device.
13. Click on the NX2C4D and then click on Change icon… to select the icon for the Nexus
unit. You can choose one of the built in icons from Rockwell Automation or click on the
Browse… button and select the NX2C4D_r01.ico icon file.
14. Click on Next> and then click on Finish to complete the installation of the AMCI NX2C4D
EDS file to the RSNetWorx system.

Once the EDS file is added to your system, add the NX2C4D to your network as you would any
other device, including adding it to the scanlist configuration of the scanner module.

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NX2C4E Ethernet Hardware Overview

Sensor 1 Sensor 2 Sensor 3 Sensor 4
1234567 1234567 1234567 1234567
Power
Status Power
LDT Status LEDs Connector
1 2 3 4
AMCI 123

RS485 + - GND
24 VDC
1 3
Nexus
2 4 Digital
Interface

Ethernet Address DIP

Status LEDs switches Switch 1 RJ45 Ethernet
Connector

Network Update Time

Both the NX2C4C and the NX2C4C-08 both have a minimum network update time of 3ms.

Ethernet IP Address

The NX2C4E uses has a default IP address of 192.168.000.XXX where “XXX” can be any
number between 1 and 254.

Every Ethernet IP unit, including those made by AMCI, has a unique MAC ID number. This
number is located directly below the label on the side of the unit and identifies the unit to the
Ethernet Network.

You can download the BOOTP software from Allen-Bradley's website. This BOOTP
software uses the MAC ID address and allows you to change the unit’s IP address. After
changing the IP address, you must cycle power to the NX2C4E to make the changes to the IP
address take affect.

The DIP switches will no longer have any function after you have changed the IP address.

Ethernet Address Selection using the DIP switches

The NX2C4E uses an IP address of 192.168.000.XXX where “XXX” can be any number between
1 and 254. Eight dip switches on the NX2C4C are used to set the “XXX” portion of the address.
Switch 8, the left most switch, is the least significant bit and switch 1, the right most switch, is the
most significant bit. The address is programmed using the following procedure.

1. Determine the address of the NX2C4E. It can be any unused address between 1 and 254.
2. Convert the address to a binary number. A value of 50 will be 0011 0010.
3. Enter the address on the dip switches. Continuing the above example, switches 8, 6, 5, 2
and 1 will be off (down) and switches 7, 4, and 3 will be on (up).

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Ethernet Status LEDs

LED Name LED Pattern Function

Number
Steady Off The module has no power or on IP address has been assigned.
Steady Green The module has at least one established Ethernet/IP connection.
1 Network Flashing Green There are no Ethernet/IP connections established to the module
Status Flashing Red One or more of the connections in which this module is
the target has timed out
Steady Red The module has detected that its IP address is already in use
Flashing Green/Red The module is performing a power on self test
Steady Off No Power.
Steady Green The module is operating correctly.
2 Module Flashing Green The module has not been initialized.
Status Flashing Red A minor recoverable fault has been detected.
Steady Red A major internal error has been detected.
Flashing Green/Red The module is performing a power on self test.
3 Activity This LED flashes green each time a packet is received or
LED transmitted
4 Link This LED indicates that the module is connected to an Ethernet
network
Setup Example
AMCI NX2C4E to Rockwell Automation 1756-ENET/B module
1. With power removed, use the dip switches to set the address of the NX2C4C.
2. Open an existing or create a new ControlLogix program.
3. From the project tree, right click on I/O configuration and select New Module.
4. From the Module Type list that appears, select 1756-ENET/B, the 1756 Ethernet Bridge
module.
5. Type a name for the Bridge module, which must begin with a letter, in the Name field.
6. Enter the slot number where the 1756-ENET/B module is located in the ControlLogix
rack.
7. In the Address/Host Name field, select the IP Address enter the desired address, for
example, 192.168.000.XXX where XXX can be a unique number between 1 and 254.
8. Click the Finish button.
9. From the project tree, right click on the 1756-ENET/B module and select New Module.
10. Select ETHERNET-MODULE Generic Ethernet Module from the list that appears and
click on OK.
11. In the module properties that appear, enter the following parameters.

Name: Your Choice (must begin with a letter)

Comm Format: Data-INT (must be Data-INT)
IP Address: 192.168.000.XXX where XXX is the number entered on the DIP switches

Assembly Instance – 100, Input – 20 for the NX2C4E

136 for the NX2C4E-08
Assembly Instance – 150, Output – 33 for the NX2C4E
33 for the NX2C4E-08
Assembly Instance – 110, Config – 0 for all versions of the Nexus LDT Interface

12. Click on Next.

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13. Select the RPI time, minimum = 3ms

14. Click on Finish.
15. Save and download the program to the ControlLogix rack.
16. While online with the PLC, right click on the Ethernet Bridge module and select
Properties.
Click on the Port Configuration tab and modify the following fields.

Enable Bootp: Unselected (This will allow the data to be manually entered in the IP
address and Domain Name fields.)
IP Address: 192.168.000.XXX (must be the same as step 7 above)
Subnet Mask: 255.255.255.0

The Gateway Address, Domain Name, Primary DNS Server Address, and Secondary DNS
Server Addresses all remain unchanged.

NX2C4P Profibus Hardware Overview

Because Profibus does not support the transfer of 136 output words, a Profibus version of the
Multiple Magnet Nexus unit, the NX2C4P-08, does not exist.

Sensor 1 Sensor 2 Sensor 3 Sensor 4

1234567 1234567 1234567 1234567
Power
Status Power
LDT Status LEDs Connector
1 2 3 4
AMCI 123

RS485 + - GND
24 VDC

1 3 Nexus
2 4 Digital
1 2 Interface

Profibus Selects Station Profibus

Status LEDs Address Female
Connector
Profibus Connector

The Nexus module uses a 9 pin female D-sub connector to communicate with the Profibus
network.

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Station Address Selection

The Nexus module has two rotary switches used to set the module’s address on the network.
Any station from 0 to 99 can be selected. Switch 1 sets the one digit and switch 2 sets the
10s digit of the address. For example, if the Nexus is to be installed at station 46, switch 1
would be set to 6, and switch 2 would be set to 4. Note, changing the station address only
takes affect at power up. Changing the address while power is applied to the Nexus module
will generate a minor fault.

Profibus Status LEDs

LED
Number LED Pattern Function
1 Red Module is Offline and no data exchange is possible
Off The module is Online
2 Green Module is Online and data exchange is possible
Off The module is Off line
3 Flashing Red 1Hz Error in configuration: IN and/or OUT length set during
initialization of the module is not equal to the length set
during the configuration of the network
Flashing Red 2Hz Error in User Parameter data: The length/contents of the
user parameter data set during initialization of the module is
not equal to the length/contents set during configuration of
the network.
Flashing Red 4Hz Error in initialization of the Profibus communication ASIC.
Off No diagnostic present
4 Off Not Used

Network Baud Rate

The NX1F2P supports the following network baud rates

9.6 kbits/sec, 19.2 kbits/sec, 93.75 kbits/sec, 187.5 kbits/sec, 500 kbits/sec, 1.5 Mbits/sec,
3 Mbits/sec, 6 Mbits/sec, and 12 Mbits/sec

Quick Start Guide

AMCI Nexus to SST-PFB-SLC Profibus interface module
1. If it is not already present, install the SST-PFB-SLC module in the SLC rack and
configure the rack (the ID code is 13635) for the module.
2. Place the PLC in program mode.
3. Connect a serial cable from the computer’s COM port to the RS232 port of the SST-PFB-
SLC module.
4. With the power off, use the rotary switches on the Nexus unit to select the desired station
address. The left switch sets the 1s digit and the right switch sets the 10s digit of the
station address.
5. Attach the Nexus unit to the Profibus network.
6. Apply power to the Nexus unit.
7. Start the SST Profibus Configuration software. (Current Version 1.9)
8. Either create a new or open an existing network.
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9. If it has not already present, register the Nexus units GSD file.

Click on Library in the toolbar and then select Add GSD file. Choose the directory
where the GSD file is located, and then select the AnyBPRfB file.

When registered this module will appear under Slaves as:

HMS Fieldbus Systems AB

ANYBUS-S PDP

10. If SST-PBF-SLC module is not already present, click on Masters. Click and drag the
Master (Rev 1.4) into the network. Right click on it and configure it according to your
system’s requirements.
11. Under slaves, click and drag the ANYBUS-S PDP module into the network. The setup
window will appear.
• Under the General tab, set the station number to match the station number set by
the rotary switches on the Nexus unit.
• Click on the Modules tab and then click on Add. The NX2C4X must be set for
28 input words and 33 output words. If a different number of words is
programmed, Network LED 3 will flash indicating an Error in the Configuration.
The input words can be located in either the Input Image table or in the M1 file,
however, all 28 input words must be located in one file. The 33 output words
must be located in the MO file.
• Click on Input 32 Byte (16 word) and then on OK.
• Click on the SLC Address tab and then select the Input Type, either I or M1, and
the offset value, that is where in the I or M1 table the data begins. It is important
not to leave gaps between an existing Profibus module and the data used by the
Nexus unit.
• Again click on the Modules tab and click on Add.
• Click on Input 16 Byte (8 word) and then on OK.
• Click on the SLC Address tab and then select the Input Type to be the same as
was selected above. Set the offset value to the value assigned to the 32 byte
parameter plus 16.
• Again click on the Modules tab and click on Add.
• Click on Input 8 Byte (4 word) and then on OK.
• Click on the SLC Address tab and then select the Input Type to be the same as
was selected above. Set the offset value to the value assigned to the 16 byte
value plus 8.
• Again click on the Modules tab and click on Add.
• Click on Output 64 Byte (32 word) and then on OK.
• Click on the SLC Address tab and then select the Output Type to be M0 and
then select an offset value. As with the input data, it is important not to leave
gaps between an existing Profibus module and the data used by the Nexus unit.
• Again click on the Modules tab and click on Add.
• Click on Output 2 Byte (1 word) and then on OK.
• Click on the SLC Address tab and then select the Output Type to be MO. Set
the offset value assigned to the 64 byte value plus 32.
• Click on OK to accept.
12. Save the network file.
13. Right click on the Master Module and select Connect from the menu that appears.

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14. Click on Yes if asked to retain the configuration.

15. Again right click on the Master Module and then select Load Configuration from the
menu that appears.
16. Place the PLC in Run mode.

NX2C4T (Modbus TCP IP) Hardware Overview

Sensor 1 Sensor 2 Sensor 3 Sensor 4
1234567 1234567 1234567 1234567
Power
Status Power
LDT Status LEDs Connector
1 2 3 4
AMCI 123

RS485 + - GND
24 VDC

1 3 Nexus
Digital
2 4 Interface

Ethernet Address DIP

switches Switch 1 RJ45 Ethernet
Status LEDs
Connector
Changing the Modbus TCP/IP Address

The NX2C4T has a default IP address of 192.168.000.XXX where “XXX” can be any number
between 1 and 254 and is set by the dip switches located on the front of the module.

Use the following procedure if you want your IP address to be something other than
192.168.000.XXX.

1. Remove power from the Nexus Unit.

2. Set all of the unit’s dip switches to the OFF (Down) position. This will set the unit’s
address to 0000 0000.
3. Start and configure your BootP server. Any DHCP/BootP server running on a
computer, which is connected to the same network, may be used for this purpose.
Please note that the Nexus Unit’s MAC ID address is located on a label on the module’s
cover.
4. Apply power to the Nexus Unit.
5. At power-up the module will attempt to get an IP address by sending several BootP
requests. This operation will require approximately 30 seconds. At this point LED2
will be flashing green. If retrieved, the IP configuration will be used and stored in the
Nexus Unit’s Flash Memory, overwriting older IP settings.
6. The Nexus Unit will now join the network with the newly set IP configuration.
7. If a BootP server is not found, the Nexus Unit will use the IP configuration that had
been previously stored in its flash memory.
8. Cycle power to the NX2C4T. The changes to the IP address will not be permanent until
power has been cycle.

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Modbus TCP/IP Address Selection using the DIP switches

The NX2C4T uses an IP address of 192.168.000.XXX where “XXX” can be any number between
1 and 254. Eight dip switches on the NX3A1X are used to set the “XXX” portion of the address.
Switch 8, the left most switch, is the least significant bit and switch 1, the right most switch, is the
most significant bit. The address is programmed using the following procedure.

1. Determine the address of the NX2C4T. It can be any unused address between 1 and 254.
2. Convert the address to a binary number. A value of 50 will be 0011 0010.
3. Enter the address on the dip switches. Continuing the above example, switches 8, 6, 5, 2
and 1 will be off (down) and switches 7, 4, and 3 will be on (up).
Modbus TCP/IP Ethernet Status LEDs

LED
Name LED Pattern Function
Number
Flashing Green with This LED indicates the number of established Modbus/TCP
Network 2 seconds interval connections to the module. The number of connections is equal
1 to the number of flashes on this LED.
Status
Flashing Green/Red Power-on self test

Steady Off No Power

Steady Green The module is operating correctly
Module Flashing Green The module has not been initialized
2
Status Flashing Red Minor recoverable fault
Steady Red Major internal error
Flashing Green/Red Power-on self test
Flashing Green This LED flashes green each time a packet is received or
3 Activity transmitted
Steady Green This LED indicates that the module is connected to an Ethernet
4 Link network

Setup Example

AMCI NX2C4T to Group Schneider’s 140 NOE 771 01 module

This setup example assumes that the 140 NOE 771 01 module has already been installed in the
PLC system.

1. With power removed, use the dip switches to set the IP address of the NX2C4T.
2. Open an existing or create a new Unity program.
3. Open the Project Browser and click on the + symbol next to Communication.
4. Click on the + symbol next to Networks to show the available networks.
5. If you are creating a new network for the NX2C4T, right click on Networks and select
New Network from the window that appears. If you are adding the NX2C4T to an
existing network, ignore this step.

Click on the down arrow to the right of the List of available Networks field and select
Ethernet from the drop down menu that appears.
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Type the new networks name in the Change Name field

Click on OK to create the new network.

6. Right click on the existing network and select open from the window that appears. The
following window will appear.

7. Enter the following parameters.

Module Family: TCP/IP 10/100 Regular Connection

Module Address: Location of the 140 NOE 771 01 module
IP Address: The TCP/IP address of the 140 NOE 771 01 module
Subnet Mask: 255.255.255.000

8. Click on the I/O scanning tab. The following screen will appear.

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Enter the following parameters.

Slave IP Address: IP Address of the NX2C4T module.

Unit ID: Not necessary for the NX2C4T module. The default value of
255 can remain.
Health Timeout: Timeout value measured in ms. Can be any value for the
NX2C4T module
Repetitive Rate: Update time of the NX2C4T in ms. A value of zero will result in
thefastest transfer of data between the NX2C4T and the NOE
module. A value other than zero must be in a multiple of 16.
RD Master Object. First destination address register where the data transmitted from
the NX2C4T will be located.
RD Slave Index: Must be 0.
RD Length: Set to 28 for the NX2C4T or 136 for the NX2C4T-08
(sixteen bit words)
Last Value (input): Status of the input registers, either last state or zero, in the event
of an error. The data from the NX2C4T will remain in the
registers if communications are lost.
WR Master Object: First source address register location where the data sent from
the PLC to the NX2C4T is located.
WR Slave Index: Must be set to 1024
WR Length: Must be set to 33 (The NX2C4T uses thirty three 16 bit output
words)
Description: Your choice of text or leave blank.

9. Close the network.

10. Click on Yes when asked “Do you want to save your modifications?”
11. Click on Yes when asked “Do you Confirm the Modification?”
12. On the Project Tree, expand the I/O configuration by clicking on the + symbol to the left
of Configuration.
13. Further expand the I/O configuration by clicking on + symbol to the left of the Local
Bus.
14. Continue to expand the I/O configuration by clicking on the + symbol to the left of the
Local Quantum Drop.
15. Continue to expand the I/O configuration by clicking on + symbol to the left of the rack
that contains the 140 NOE 771 01 module.
16. Expand the networks attached to the NOE module by clicking on the + symbol to the left
of the 140 NOE 771 01 module.
17. Right click on the network associated with the 140 NOE 771 01 module and select OPEN
from the window that appears.
18. Click on the down arrow on the field just below where it asks you to “Please choose a
Network.” Select the network that was created above.
19. Save and build the project, and download it to the PLC. If the NX2C4T is powered up
and attached to the network, network LED 3 (the upper right network status LED) should
now be flashing and network LED 4 (the lower right network status LED) should now be
on solid.

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Chapter 7: Manual Revision History

Version 1.0 added details to the specifications and a more complete hardware description.

Version 1.1 added the update time of the NX2C4X-08 and updated the ControlNet setup
procedures.

Version 1.2 changed the SSI update time to 500µs (this change was made for the V1 firmware)
and added a note on how programming the channel and applying the preset value on a
NX2C4X and a NX2C4X-08 at the same time will cause a command error.

Version 1.3 was released on 12/6/01 and added a column to the input data tables. One column
shows that the PLC-5 input data starts at word 0 and a second shows that the ControlLogix
input data starts at word 2.

Version 1.4 was released on 3/18/02. Dimensions were added. The references to the RSLogix
revisions were removed from the quickstart guide.

Version 1.5 was released on 10/15/02. A note was added that the Nexus unit interfaces with
sensors whose output signals are at 5Vdc, regardless of the sensor’s power supply.

Version 1.6 was released on 4/28/05. This version added a note to the functionality of ControlNet
LED 3.

Version 1.7 was released on 5/11/05. This version removed the SSI functionality, and added the
DeviceNet, Ethernet, and Profibus networks to the specifications. The Hardware overview
and wiring as also moved to the beginning of the specifications. Notes were added that
because of the number of words used, the NX2C4D-08 and the NX2C4P-08 are not
available.

Version 1.8 was released on 7/23/07. This version added mounting information and increased the
number of input words from 20 to 28. This was changed for the NX2C4P unit. Existing
customers with NX2C4C and NX2C4E units can still set the number of input words to 22
and 20 respectively.

Version 1.9 was released on 6/9/10. This revision added outline drawings, specifications,
programmable parameters, and using the Modbus TCP/IP to the specifications.

File: Nexus_LDT_specifications.doc
date: 6/9/10

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