aspar SDM-8AO 8 Analog Outputs Expansion Module User Manual
aspar SDM-8AO 8 Analog Outputs Expansion Module

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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 verifica tion. We reserve the right to change product specifications without notice. Please read the instructions carefully and follow the recommendations contained therein.

WARNING ICON 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

Purpose and description of the module
The SDM-8AO module has a set of 8 analog outputs that could work as a current output (0-20mA or 4-20mA) or as a voltage output (0-10V). Setting the output curent 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.

Technical Specifications

  Power Supply Voltage 10-30 VDC; 10-28VAC
Maximum Current* DC: 52 mA @ 24VDC AC: 62 mA @ 24VAC
Maximum power consumption DC: 1,25W; AC: 1,5VA
    Outputs No of outputs 8
Voltage output 0V do 10V ( resolution 1.5mV)
Current output 0mA do 20mA ( resolution 5μA)
Current output 4mA do 20mA (value in ‰ – 1000 steps) (resolution 16μA)
Measurement resolution 12 bits
ADC processing time 16ms / channel
 Temperature Work -10 °C – +50°C
Storage -40 °C – +85°C
  Connectors Power Supply 2 pins
Communication 3 pins
Outputs 2x 10 pins
Configuration Mini USB
 Size Height 110 mm
Length 62 mm
Width 88 mm
Interface RS485 Up to 128 devices

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. Power connectors, communication and IOs are at the bottom and top of the module. USB connector configuration and indicators located on the front of the module.

Dimensions

Communication configuration

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.

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.

Setting Module Address in RS485 Modbus Network
The following table shows how to set switch to determine the address of the module. The module address is set with the switches in the range of 0 to 127. Addresses From 128 to 255 can by set via RS485 or USB.

Switch Address
SW1 +1
SW2 +2
SW3 +4
SW4 +8
SW5 +16
SW6 +32
SW7 +64

Ex. if switches 1, 3 and 5 are on than module addres is:
Address = 1 + 4 + 16 = 21

Types of Modbus Registers
There are 4 types of variables available in the modul

Typ e Beginning address Variable Access Modbus Command
1 00001 Digital Outputs BitRead & 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

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

Default settings
You can restore the default configuration by the switch SW8 (see 3.5.2 – Restore the default configuration)

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

Restore the default configuration
To restore the default configuration:

  • turn off the power
  • turn on the switch SW8
  • turn on the power
  • when power and communication LED start blinking alternately than turn off the switch SW8
    Caution! After restoring the default configuration all values stored in the registers will be cleared as well.

Configuration registers

Modbus Dec Hex Name Values
   40003    2    0x02    Baud rate 0 – 24001 – 48002 – 96003 – 192004 – 384005 – 576006 – 115200other – value * 10
  40005   4   0x04   Parity 0 – none1 – odd2 – even3 – always 14 – always 0
40004 3 0x03 Stop Bits LSB 1 – one stop bit 2 – 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 – RTU1 – ASCII

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.

Switches

Switches

Switch Function Description
1 Module address +1     Setting module address from 0 to 127
2 Module address +2
3 Module address +4
4 Module address +8
5 Module address +16
6 Module address +32
7 Module address +64
8 Restoring default settings Restoring default settings(see 3.5.2 Restore the default configuration).

Front panel removing

To remove the panel and gain access to the switch, you must pry open the panel using a thin tool (eg a small screwdriver) as in the picture below.

Front panel removing

Indicators

Indicators

Indicator Description
Power supply LED indicates that the module is correctly powered.
Communication The LED lights up when the unit received the correct packet and sends the answer.
Outputs state LED indicates that the output is on.

Module Connection

Analog outputs
Analog outputs

Power supply of analog outputs
Power supply of analog outputs

Communication, power supply
Communication, power supply

Setting output mode

Each of outputs can be configured as a voltage outputs or a current outputs. To change the operating mode in addition to configuration changes by using the program or via RS485, also set the jumpers inside the module as shown below

Jumper Description
Jumper Current output (default)
Jumper Voltage output

Setting output mode

Opening the housing

Opening the housing

  1. Remove the clip by pressing it and moving toward the center of the housing
  2. Separate the housing gently tilting the clamps using a thin tool.

Modules Registers

Modbus Dec Hex Register Name Access Description
30001 0 0x00 Version/Type Read Version and Type of the device
30002 1 0x01 Switches Read Switches state
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
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 Outputs Read Bit is set if value ≠ 0
40053 52 0x34 Analog output 1 Read & Write Value of analog output: in mV for voltage output (max 10240) in μA for current output 0 – 20mA (max 20480) in ‰ for current output 4-20mA (max 1000)
40054 53 0x35 Analog output 2 Read & Write
40055 54 0x36 Analog output 3 Read & Write
40056 55 0x37 Analog output 4 Read & Write
40057 56 0x38 Analog output 5 Read & Write
40058 57 0x39 Analog output 6 Read & Write
40059 58 0x3A Analog output 7 Read & Write
40060 59 0x3B Analog output 8 Read & Write
40061 60 0x3C Default output 1 value Read & Write     Default value of output set when power is on or when watchdog reset occurs
40062 61 0x3D Default output 2 value Read & Write
40063 62 0x3E Default output 3 value Read & Write
40064 63 0x3F Default output 4 value Read & Write
40065 64 0x40 Default output 5 value Read & Write
40066 65 0x41 Default output 6 value Read & Write
40067 66 0x42 Default output 7 value Read & Write
40068 67 0x43 Default output 8 value Read & Write
40069 68 0x44 Output 1 setting Read & Write Setting of output mode:
70 69 0x45 Output 2 setting Read & Write
Modbus Dec Hex Register Name Access Description
40071 70 0x46 Output 3 setting Read & Write     0 – output disable 1 – voltage output– current output 0-20mA– current output 4-20mA
40072 71 0x47 Output 4 setting Read & Write
40073 72 0x48 Output 5 setting Read & Write
40074 73 0x49 Output 6 setting Read & Write
40075 74 0x4A Output 7 setting Read & Write
40076 75 0x4B Output 8 setting Read & Write

Bit access

Modbus Address Dec Address Hex Address Register name Access Description
801 800 0x320 Output 1 Read     If voltage or current is greater than 0 then according bit is set.
802 801 0x321 Output 2 Read
803 802 0x322 Output 3 Read
804 803 0x323 Output 4 Read
805 804 0x324 Output 5 Read
806 805 0x325 Output 6 Read
807 806 0x326 Output 7 Read
808 807 0x327 Output 8 Read

Configuration software

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.

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

Configurator

Manufactured 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 SDM-8AO 8 Analog Outputs Expansion Module [pdf] User Manual
SDM-8AO, 8 Analog Outputs Expansion Module, SDM-8AO 8 Analog Outputs Expansion Module, Analog Outputs Expansion Module, Outputs Expansion Module, Expansion Module, Module

References

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