RS 485 Mini Modbus 1AO

Expansion Module – 1 analog output, 2 digital inputs

Version 1.6 User Manual

Manufactured for
 RS485 Mini Modbus 1AO
User Manual

Thank you for choosing our product.

This manual will help you with proper support and proper operation of the device.

The information contained in this manual have been prepared with utmost care by our
professionals and serve as a description of the product without incurring any liability for
the purposes of commercial law.

This information does not release you from the obligation of own judgment and
verification.

We reserve the right to change product specifications without notice.

Please read the instructions carefully and follow the recommendations contained
therein.

WARNING!

Failure to follow instructions can result in equipment damage or impede

the use of the hardware or software.

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1. Safety rules
• Before first use, refer to this manual;

• Before first use, make sure that all cables are connected properly;

• Please ensure proper working conditions, according to the device specifications

(eg: supply voltage, temperature, maximum power consumption);

• Before making any modifications to wiring connections, turn off the power supply.

2. Module Features
2.1. Purpose and description of the module
The MOD-1AO module has 1 current analog output (0-20mA lub 4-20mA) and
1 voltage analog output (0-10V). Both outputs can be used at the same time. The modul
is equipped in two digital inputs. In addition, terminals IN1 and IN2 can be used to
connect one encoder. Setting the output current or voltage value is done via RS485
(Modbus protocol), so you can easily integrate the module with popular PLCs, HMI or
PC equipped with the appropriate adapter.

This module is connected to the RS485 bus with twisted-pair wire.

Communication is via MODBUS RTU or MODBUS ASCII. The use of 32-bit ARM
core processor provides fast processing and quick communication. The baud rate is
configurable from 2400 to 115200.

The module is designed for mounting on a DIN rail in accordance with

DIN EN 5002.

The module is equipped with a set of LEDs used to indicate the status of inputs
and outputs useful for diagnostic purposes and helping to find errors.

Module configuration is done via USB by using a dedicated computer program.

You can also change the parameters using the MODBUS protocol.

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2.2. Technical Specifications

Voltage 10-38VDC; 20-28VAC

Power supply
Power consumption 2 W @ 24 VDC; 4 VA @ 24 VAC
Isolation Isolation between power supply and I/O 1000 VDC
Number of analog outputs 2 (voltage x 1, current x 1)
0V - 10V (resolution 1.5mV)
Voltage output Max, current load: 50mA
Accuracy: ±2%
0mA - 20mA ( resolution 5μA);
Analog output 4mA - 20mA (value in ‰ – 1000 steps)
Current output ( resolution 16μA)
Max. resistance: 500Ω
Accuracy: ±1%
Output resolution 12 bits
DAC time processing 16ms / channel
Number of digital intputs 2
Voltage range 0 – 36V
Low state„0” 0 – 3V
High state „1” 6 – 36V
Digital input
Input impedance 4kΩ
Isolation 1500 Vrms
Input type PNP or NPN
Number of counters 2
Resolution 32 bits
Counters Frequency 1kHz (max)
Impulse width 500 μs (min.)
Encoder support YES
Operating temperature -10 °C - +50°C
Environmental Storage temperature -40 °C - +85°C
conditions Relative humidity 5-95%RH (without condensation)
Ingress protection IP40
Power Supply 2 screw connector
RS485 3 screw connector
Connectors Inputs & Outputs 3 (AO) + 3 (DI) screw connector
Configuration Mini USB, type B
Max. cable size 2,5 mm2 (18...12 AWG)

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Material Self-extinguishing plastic (PC/ABS)

Housing
Mounting DIN rail (DIN norma EN 50022)
Wymiary Height / Depth / Width 90 mm / 56 mm / 17 mm
RS485 Up to 128 devices
Interfejs
Communication protocol Modbus RTU/ASCII, slave

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2.3. Dimensions of the product

Look and dimensions of the module are shown below. The module is mounted
directly to the rail in the DIN industry standard.

56
50
34

17
90

3. Communication configuration
3.1. Grounding and shielding
In most cases, IO modules will be installed in an enclosure along with other
devices which generate electromagnetic radiation. Examples of these devices are relays
and contactors, transformers, motor controllers etc. This electromagnetic radiation can
induce electrical noise into both power and signal lines, as well as direct radiation into
the module causing negative effects on the system. Appropriate grounding, shielding
and other protective steps should be taken at the installation stage to prevent these
effects. These protective steps include control cabinet grounding, module grounding,
cable shield grounding, protective elements for electromagnetic switching devices,
correct wiring as well as consideration of cable types and their cross sections.
3.2. Network Termination
Transmission line effects often present a problem on data communication
networks. These problems include reflections and signal attenuation.

To eliminate the presence of reflections from the end of the cable, the cable must
be terminated at both ends with a resistor across the line equal to its characteristic
impedance. Both ends must be terminated since the direction of propagation is bi-
directional. In the case of an RS485 twisted pair cable this termination is typically
120 Ω.

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3.3. Types of Modbus Registers

There are 4 types of variables available in the module
Beginning Modbus
Type Variable Access
address Command
Bit
1 00001 Digital Outputs 1, 5, 15
Read & Write
Bit
2 10001 Digital Inputs 2
Read
Registered
3 30001 Input Registers 3
Read
Registered
4 40001 Output Registers 4, 6, 16
Read & Write

3.4. Communication settings

The data stored in the modules memory are in 16-bit registers. Access to
registers is via MODBUS RTU or MODBUS ASCII.

3.4.1. Default settings

Name of parameter Value

Address 1
Baud rate 19200
Parity No
Data bits 8
Stop bits 1
Reply Delay [ms] 0
Modbus type RTU

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3.4.2. Configuration registers

Address Name Values

40002 Module address From 0 to 255
40003 Baud rate 0 – 2400
1 – 4800
2 – 9600
3 – 19200
4 – 38400
5 – 57600
6 – 115200
other – value * 10
40005 Parity 0 – none
1 – odd
2 – even
3 – always 1
4 – always 0
40004 Stop Bits LSB 1 – one stop bit
2 – two stop bits
40004 Data Bits MSB 7 – 7 data bits
8 – 8 data bits
40005 Response Delay Time in ms
40007 Modbus Mode 0 – RTU
1 – ASCII

3.4.3. Watchdog function

This 16-bit register specifies the time in milliseconds to watchdog reset. If module does
not receive any valid message within that time, all Digital and Analog Outputs will be
set to the default state.

This feature is useful if there is an interruption in data transmission and for security
reasons. Output states must be set to the appropriate state in order to assure the safety
of persons or property.

The default value is 0 milliseconds which means the watchdog function is disabled.

Range: 0-65535 ms

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4. Indicators

Indicator Description
ON LED indicates that the module is correctly powered.
TX The LED lights up when the unit received the correct packet and sends the answer.
AOV The LED lights up when the output voltage is non-zero.
AOI The LED lights up when the output current is non-zero.
DI1, DI2 Input state 1, 2

5. Block diagram

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6. Module Connection
6.1. Analog outputs, digital intputs

6.2. Communication, power supply

Communication Power supply, 24DC Voltage Power supply, 24AC Voltage

Power supply

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Power supply

Power supply
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7. Modules Registers
7.1. Registered access
Address
Register Name Access Description
Modbus Dec Hex
30001 0 0x00 Version/Type Read Version and Type of the device
40002 1 0x01 Address Read & Write Module Address
40003 2 0x02 Baud rate Read & Write RS485 baud rate
40004 3 0x03 Stop Bits Read & Write No of Stop bits
40005 4 0x04 Parity Read & Write Parity bit
40006 5 0x05 Response Delay Read & Write Response delay in ms
40007 6 0x06 Modbus Mode Read & Write Modbus Mode (ASCII or RTU)
40009 8 0x09 Watchdog Read & Write Watchdog
40033 32 0x20 Received packets LSB Read & Write
No of received packets
40034 33 0x21 Received packets MSB Read & Write
40035 34 0x22 Incorrect packets LSB Read & Write
No of received packets with error
40036 35 0x23 Incorrect packets MSB Read & Write
40037 36 0x24 Sent packets LSB Read & Write
No of sent packets
40038 37 0x25 Sent packets MSB Read & Write
30051 50 0x32 Inputs Read Input state; Bit is set if value ≠ 0
30052 51 0x33 Outputs Read Output state; Bit is set if value ≠ 0
Value of analog output:
inμA for
0 - 20mA (max 20480)
40053 52 0x34 Current analog output 1 Read & Write
in ‰ for
4-20mA (max 1000)
Value of analog output:
40054 53 0x35 Voltage analog output 2 Read & Write
in mV (max 10240)
40055 54 0x36 Counter 1 LSB Read & Write
32-bit counter 1
40056 55 0x37 Counter 1 MSB Read & Write
40057 56 0x38 Counter2 LSB Read & Write
32-bit counter 2
40058 57 0x39 Counter 2 MSB Read & Write
40059 58 0x3A CounterP 1 LSB Read & Write
32-bit value of captured counter 1
40060 59 0x3B CounterP 1 MSB Read & Write

40061 60 0x3C CounterP 2 LSB Read & Write

32-bit value of captured counter 2
40062 61 0x3D CounterP 2 MSB Read & Write
40063 62 0x3E Catch Read & Write Catch counter
40064 63 0x3F Status Read & Write Captured counter
Default value of 1 analog The default of analog output set at power supply and due to
40065 64 0x40 Read & Write
current output activation of watchdog.

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Address
Register Name Access Description
Modbus Dec Hex
Default value of 2 analog The default of analog output set at power supply and due to
40066 65 0x41 Read & Write
voltage output activation of watchdog.
Current analog output configuration:
Current analog output 1
40067 66 0x42 Read & Write 0 – OFF
configuration
2 – current output 0-20mA
3 – current output 4-20mA
Voltage analog output 2 0 – OFF
40068 67 0x43 Read & Write
configuration 1 – voltage output
40069 68 0x44 Counter Config 1 Read & Write Counters configuration:
+1 – time measurement (if 0 counting impulses)
+2 – autocetch counter every 1 sec
+4 – catch value when input low
40070 69 0x45 Counter Config 2 Read & Write +8 – reset counter after catch
+16 – reset counter if input low
+32 – encoder

7.2. Bit access

Modbus Dec Hex

Register Name Access Description
Address Address Address
801 800 0x320 Input 1 Read Input 1 state
802 801 0x321 Input 2 Read Input 2 state
Current Analog Output state; Bit is set if
817 816 0x330 Output 1 Read
value ≠ 0
Voltage Analog Output state; Bit is set if
818 817 0x331 Output 2 Read
value ≠ 0
993 992 0x3E0 Capture 1 Read & Write Capture counter 1
994 993 0x3E1 Capture 1 Read & Write Capture counter 1
1009 1008 0x3F0 Captured 1 Read & Write Captured value of counter 1
1010 1009 0x3F1 Captured 2 Read & Write Captured value of counter 2

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8. Configuration software
Modbus Configurator is software that is designed to set the module registers
responsible for communication over Modbus network as well as to read and write the
current value of other registers of the module. This program can be a convenient way to
test the system as well as to observe real-time changes in the registers. Communication
with the module is done via the USB cable. The module does not require any drivers

USB Cable

Modbus
Module

Configurator is a universal program, whereby it is possible to configure all

available modules.

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Spis treści
1. Safety rules.......................................................................................................................................3
2. Module Features...............................................................................................................................3
2.1. Purpose and description of the module.....................................................................................3
2.2. Technical Specifications...........................................................................................................4
2.3. Dimensions of the product........................................................................................................6
3. Communication configuration..........................................................................................................6
3.1. Grounding and shielding...........................................................................................................6
3.2. Network Termination................................................................................................................6
3.3. Types of Modbus Registers.......................................................................................................7
3.4. Communication settings...........................................................................................................7
3.4.1. Default settings.................................................................................................................7
3.4.2. Configuration registers......................................................................................................8
3.4.3. Watchdog function............................................................................................................8
4. Indicators..........................................................................................................................................9
5. Block diagram..................................................................................................................................9
6. Module Connection........................................................................................................................10
6.1. Analog outputs, digital intputs................................................................................................10
6.2. Communication, power supply...............................................................................................10
7. Modules Registers..........................................................................................................................11
7.1. Registered access....................................................................................................................11
7.2. Bit access................................................................................................................................12
8. Configuration software...................................................................................................................13

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