aspar - logoMini Modbus 4DI-M
Expansion Module – 4 digital inputs with counters memory
Version 1.4
User Manualaspar Mini Modbus 4DI-M Expansion Module

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 judgement 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.

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

Module Features

2.1. Purpose and description of the module
4DI Module is an innovative device that provides a simple and cost-effective extension of the number of lines of input in popular PLCs.
The module has 4 digital inputs with configurable timer/counter option, which allow to connect two encoders. All inputs are isolated from the logic by optocouplers.
Each channel can be individually configured in one of several modes.
The module has a fast non-volatile FRAM memory that stores values of the counters and the counters captured. This means that even after a power failure, these values are  stored and can further use when the power returns.
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.

2.2. Technical Specifications

Power Supply Voltage 10-38VDC; 20-28VAC
Maximum Current’ 62 mA @ 12V / 35 mA @ 24V
Digital Inputs No of inputs 4
Voltage range 0 — 36V
Low State .0″ 0 — 3V
High State „1″ 6 — 36V
Input impedance 4k0
Isolation 1500 Vrms
Input Type PNP or NPN
Counters No 4
Resolution 32 bits
Frequency lkHz (max)
Impulse Width 500 ps (min)
Temperature Work -10 °C – +50°C
Storage -40 °C – +85°C
Connectors Power Supply 3 pin
Communication 3 pin
Inputs 2 x3 pin
Configuration Mini USB
Size Height 90 mm
Length 56 mm
Width 17 mm
Interface RS485 Up to 128 devices

* Maximum current with active Modbus transmission and high state on all inputs

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. aspar Mini Modbus 4DI-M Expansion Module - Dimensions

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 bidirectional.
In the case of an RS485 twisted pair cable this termination is typically 120 Ω.

3.3. Types of Modbus Registers
There are 4 types of variables available in the module

Type Beginning
address
Variable Access Modbus
Command
1 1 Digital Outputs Bit
Read & Write
1′ 5′ 15
2 10001 Digital Inputs Bit Read 2
3 30001 Input Registers
Registered Read 3
4 40001 Output Registers Registered Read & Write 4′ 6, 16

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

Parameter name Value
Address 1
Baud rate 19200
Parity No
Data bits 8
Stop bits 1
Reply Delay [ms] 0
Modbus Type RTU

3.4.2. Configuration registers

Modbus Dec Hex Name Values
Address
40003
40005
2 0x02 Baud rate 0 – 2400
1 – 4800
2 — 9600
3 — 19200
4 – 38400
5 – 57600
6 – 115200
other – value * 10
4 0x04 Parity 0 – none
1 – odd
2 – even
3 — always 1
4 – always 0
40004 3 0x03 Stop Bits LSB 1
2 – one stop bit
– two stop bits
40004 3 0x03 Data Bits MSB 7 – 7 data bits8 – 8 data bits
40006 5 0x05 Response delay Time in ms
40007 6 0x06 Modbus Mode 0 – RTU
1 -ASCII

Indicators

aspar Mini Modbus 4DI-M Expansion Module - 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.
1, 2, 3, 4 LED indicates that on the input is high state.

Block diagram

aspar Mini Modbus 4DI-M Expansion Module - diagram

Module Connection

Input connectionaspar Mini Modbus 4DI-M Expansion Module - Module

Modules Registers

7.1. Registered access

Modbus Dec Hex Register Name Access Description
30001 0 Ox00 Version/Type Read Version and Type of the device
30002 1 0x01 Address Read Module Address
40003 2 0x02 Baud rate Read & Write RS485 baud rate
40004 3 0x03 Stop Bits & Data Bits Read & Write No of Stop bits & Data Bits (see 3.4.2)
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 0x08 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 Inputs state
40053 52 0x34 Counter 1 LSB Read & Write 32-bit counter 1
40054 53 0x35 Counter 1 MSB Read & Write
40055 54 0x36 Counter 2 LSB Read & Write 32-bit counter 2
40056 55 0x37 Counter 2 MSB Read & Write
40057 56 0x38 Counter 3 LSB Read & Write 32-bit counter 3
40058 57 0x39 Counter 3 MSB Read & Write
40059 58 Ox3A Counter 4 LSB Read & Write 32-bit counter 4
40060 59 Ox3B Counter 4 MSB Read & Write
40061 60 Ox3C CCounter 1 LSB Read & Write 32-bit value of captured counter 1
40062 61 Ox3D CCounter 1 MSB Read & Write
40063 62 Ox3E CCounter 2 LSB Read & Write 32-bit value of captured counter 2
40064 63 0x3F CCounter 2 MSB Read & Write
40065 64 0x40 CCounter 3 LSB Read & Write 32-bit value of captured counter 3
40066 65 0x41 CCounter 3 MSB Read & Write
40067 66 0x42 CCounter 4 LSB Read & Write 32-bit value of captured counter 4
40068 67 0x43 CCounter 4 MSB Read & Write
40069 68 0x44 Counter Confg 1 Read & Write Counter Configuration
+1 — time measurement (if 0 counting impulses)
+2 — autocatch counter every 1 sec
+4 — catch value when input low
+8 — reset counter after catch
+16 — reset counter if input low
+32 — encoder
40070 69 0x45 Counter Confg 2 Read & Write
40071 70 0x46 Counter Confg 3 Read & Write
40072 71 0x47 Counter Confg 4 Read & Write
40073 72 0x48 Catch Read & Write Catch counter
40074 73 0x49 Status Read & Write Captured counter

7.2. Bit access

Modbus
Address
Dec
Address
Hex
Address
Register name Access Description
10801 800 0x320 Input 1 Read Input 1 state
10802 801 0x321 Input 2 Read Input 2 state
10803 802 0x322 Input 3 Read Input 3 state
10804 803 0x323 Input 4 Read Input 4 state
1153 1152 0x480 Capture 1 Read & Write Capture counter 1
1154 1153 0x481 Capture 2 Read & Write Capture counter 2
1155 1154 0x482 Capture 3 Read & Write Capture counter 3
1156 1155 0x483 Capture 4 Read & Write Capture counter 4
1169 1168 0x490 Captured 1 Read & Write Captured value of counter 1
1170 1169 0x491 Captured 2 Read & Write Captured value of counter 2
1171 1170 0x492 Captured 3 Read & Write Captured value of counter 3
1172 1171 0x493 Captured 4 Read & Write Captured value of counter 4

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.aspar Mini Modbus 4DI-M Expansion Module - drivers

Configurator is a universal program, whereby it is possible to configure all available modules.aspar Mini Modbus 4DI-M Expansion Module - Configurator

aspar - logoManufactured for:
Aspar s.c.
ul. Oliwska 112
80-209 Chwaszczyno
Poland
ampero@ampero.eu
www.ampero.eu
Tel. +48 58 351 39 89; +48 58 732 71 73

Documents / Resources

aspar Mini Modbus 4DI-M Expansion Module [pdf] User Manual
Mini Modbus 4DI-M, Expansion Module, Mini Modbus 4DI-M Expansion Module, Module

References

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