iSMA CONTROLLI SfAR-S-8AI2DO User manual

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DMP273en | 3rd Issue rev. 2 | 05/2022
SfAR-S-8AI2DO
User Manual
Expansion Module - 8 Analog Inputs, 2
Digital Outputs
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Table of Contents
1 Introduction ............................................................................................................................. 4
1.1 Revision History................................................................................................................................4
2 Safety Rules.............................................................................................................................. 5
3 Module Features..................................................................................................................... 6
3.1 Purpose and Description of the Module ...................................................................................6
3.2 Technical Specification ...................................................................................................................6
3.3 Dimensions .......................................................................................................................................7
4 Communication....................................................................................................................... 9
4.1 Grounding and Shielding...............................................................................................................9
4.2 Network Termination......................................................................................................................9
4.3 Setting Module Address in RS485 Modbus Network .............................................................9
4.4 Types of Modbus Functions....................................................................................................... 11
4.5 Communication Settings............................................................................................................. 11
4.5.1 Default Settings....................................................................................................................... 11
4.6 Configuration Registers............................................................................................................... 12
5 Indicators................................................................................................................................ 13
6 Connections........................................................................................................................... 14
6.1 Block Diagram ............................................................................................................................... 14
6.2 Power Supply Connection .......................................................................................................... 14
6.2.1 DC Power Connection ........................................................................................................... 14
6.2.2 AC Power Connection............................................................................................................ 15
6.3 Communication Bus Connection.............................................................................................. 15
6.4 Connection of Analog Inputs ..................................................................................................... 15
6.4.1 Connection of Current Measurement............................................................................... 15
6.4.2 Connection of Voltage Measurement................................................................................ 16
6.5 Connection of Digital Outputs................................................................................................... 16
6.5.1 Connection of PNP Output .................................................................................................. 16
6.5.2 Connection of NPN Output.................................................................................................. 16
6.6 Quick Connector........................................................................................................................... 16
7 Selecting Input Mode........................................................................................................... 18
7.1 Opening the Case......................................................................................................................... 18
8 Analog Filtering...................................................................................................................... 19
9 DIP Switch............................................................................................................................... 20
10 Module Registers.................................................................................................................. 21

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10.1 Registered Access......................................................................................................................... 21
10.2 Bit Access........................................................................................................................................ 24
11 Configuration Software ....................................................................................................... 26

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1 Introduction
Thank you for choosing our product.
This manual will help you with proper handling and operating of the device.
The information included 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 discharge you from the
liability of your own judgement and verification.
We reserve the right to change product specifications without notice.
Please read the instructions carefully and follow the recommendations concluded
therein.
1.1 Revision History
Rev. Date Description
3.2 25 May 2022 Rebranded
Table 1. Revision history
WARNING!
Failure to follow instructions can result in equipment damage or impede the use of
the hardware or software.

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2 Safety Rules
Improper wiring of the product can damage it and lead to other hazards. Make sure
that the product has been correctly wired before turning the power on.
Before wiring or removing/mounting the product, make sure to turn the power off.
Failure to do so might cause an electric shock.
Do not touch electrically charged parts such as power terminals. Doing so might cause
an electric shock.
Do not disassemble the product. Doing so might cause an electric shock or faulty
operation.
Use the product only within the operating ranges recommended in the specification
(temperature, humidity, voltage, shock, mounting direction, atmosphere, etc.). Failure
to do so might cause a fire or faulty operation.
Firmly tighten the wires to the terminal. Failure to do so might cause a fire.
Avoid installing the product in close proximity to high-power electrical devices and
cables, inductive loads, and switching devices. Proximity of such objects may cause an
uncontrolled interference, resulting in an instable operation of the product.
Proper arrangement of the power and signal cabling affects the operation of the entire
control system. Avoid laying the power and signal wiring in parallel cable trays. It can
cause interferences in monitored and control signals.
It is recommended to power controllers/modules with AC/DC power suppliers. They
provide better and more stable insulation for devices compared to AC/AC transformer
systems, which transmit disturbances and transient phenomena like surges and bursts
to devices. They also isolate products from inductive phenomena from other
transformers and loads.
Power supply systems for the product should be protected by external devices limiting
overvoltage and effects of lightning discharges.
Avoid powering the product and its controlled/monitored devices, especially high
power and inductive loads, from a single power source. Powering devices from a single
power source causes a risk of introducing disturbances from the loads to the control
devices.
If an AC/AC transformer is used to supply control devices, it is strongly recommended
to use a maximum 100 VA Class 2 transformer to avoid unwanted inductive effects,
which are dangerous for devices.
Long monitoring and control lines may cause loops in connection with the shared
power supply, causing disturbances in the operation of devices, including external
communication. It is recommended to use galvanic separators.
To protect signal and communication lines against external electromagnetic
interferences, use properly grounded shielded cables and ferrite beads.
Switching the digital output relays of large (exceeding specification) inductive loads can
cause interference pulses to the electronics installed inside the product. Therefore, it
is recommended to use external relays/contactors, etc. to switch such loads. The use
of controllers with triac outputs also limits similar overvoltage phenomena.
Many cases of disturbances and overvoltage in control systems are generated by
switched, inductive loads supplied by alternating mains voltage (AC 120/230 V). If they
do not have appropriate built-in noise reduction circuits, it is recommended to use
external circuits such as snubbers, varistors, or protection diodes to limit these effects.

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3 Module Features
3.1 Purpose and Description of the Module
The SfAR-S-8AI2DO module allows for measuring voltages and currents. Values are read
via RS485 (Modbus), so the module can be easily integrated with popular PLCs, HMI, or
PC equipped with the appropriate adapter.
The device has a set of 8 analog inputs measurements. In addition, the module is
equipped with 2 configurable digital outputs.
This module is connected to the RS485 bus with a 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 to indicate the status of inputs and outputs
which is useful for diagnostic purposes and helping to find errors.
Module configuration is done via USB by using a dedicated computer program. It also
allows for changing the parameters using the Modbus protocol or set the Modbus
address using the DIP switches under the front panel.
3.2 Technical Specification
Power Supply Voltage 10-38 V DC; 10-28 V AC
Power consumption (with active Modbus transmission, all
outputs on and high state on all inputs)
2.4 W at 24 V DC
3 VA at 24 V AC
Inputs No. of inputs 8
Absolute maximum input voltage ±30 V
Voltage input impedance 120 kΩ
Voltage measurement accuracy ±0.2 %
Voltage input mode
0-10 V
-10-10 V
Max. voltage ±12.288 V
Resolution 1.5 mV
Voltage input mode
0.1 V
-1.1 V
Max. voltage ±3.072 V
Resolution 1 mV
Absolute maximum input current ±35 mA
Current input impedance 100 Ω
Current measurement accuracy ±0.2 %

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Current input mode
0-20 mA
-20-20 mA
Max. current ±30.72 mA
Resolution 3.75 μA
Current input mode
4-20 mA
Max. current 20 mA
Resolution 1 ‰
ADC processing time 16 ms/channel
Isolation 1000 V DC
Digital Outputs Maximum current and voltage 500 mA/55 V
Isolation 1000 V DC
Temperature Work -10°C to +50°C (14°F to 122°F)
Storage -40°C to +85°C (-40°F to 185°F)
Connectors Power Supply 2 pin
Communication 3 pin
Inputs & outputs 2 x 10 pin
Quick connector IDC10
Configuration mini USB
Size Height 119.1 mm (4.689 in)
Length 110.9 mm (4.366 in)
Width 22.7 mm (0.894 in)
Interface RS485 Up to 128 devices
Table 2. Technical specification
3.3 Dimensions
The appearance 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 I/Os are at the bottom and top of the module. USB connector
configuration and indicators are located on the front of the module.

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Figure 1. Dimensions

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4 Communication
4.1 Grounding and Shielding
In most cases, I/O modules will be installed in an enclosure along with other devices,
which generate electromagnetic radiation. Relays, contactors, transformers, motor
controllers, etc. are examples of such devices. Radiation can induce electrical noise into
both power and signal lines, as well as direct radiation into the module. Whether or not
the SfAR modules are immune to such effects, the interferences must be suppressed at
their source if possible to ensure the proper functioning of the entire system.
Appropriate grounding, shielding and other protective steps should be taken at the
installation stage to prevent these effects. It is recommended to at least follow the rules
below:
line power cables must be routed with spatial separation from signal and data
transmission cables;
analog and digital signal cables should also be separated;
it is recommended to use shielded cables for analog signals, cable shields should not
be interrupted by intermediate terminals;
the shielding should be earthed directly after the cable enters the cabinet.
It is recommended to install interference suppressors when switching inductive loads
(e.g., coils of contactors, relays, solenoid valves). RC snubbers or varistors are suitable for
AC voltage and freewheeling diodes for DC voltage loads. The suppressing elements must
be connected as close to the coil as possible.
4.2 Network Termination
Transmission line effects often represent the problem of data communication networks.
These problems include reflections and signal attenuation.
To eliminate the presence of reflections at the end of the cable, the cable must be
terminated at both ends with a resistor across the line adequate to its characteristic
impedance. Both ends must be terminated since the direction of propagation is
bidirectional. In case of RS485 twisted pair cable, this termination is typically 120Ω.
4.3 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 31. Addresses from 32 to 255
can be set via RS485 or USB.
Addr SW1 SW2 SW3 SW4 SW5
0 OFF OFF OFF OFF OFF
1 ON OFF OFF OFF OFF
2 OFF ON OFF OFF OFF
3 ON ON OFF OFF OFF
4 OFF OFF ON OFF OFF

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Addr SW1 SW2 SW3 SW4 SW5
5 ON OFF ON OFF OFF
6 OFF ON ON OFF OFF
7 ON ON ON OFF OFF
8 OFF OFF OFF ON OFF
9 ON OFF OFF ON OFF
10 OFF ON OFF ON OFF
11 ON ON OFF ON OFF
12 OFF OFF ON ON OFF
13 ON OFF ON ON OFF
14 OFF ON ON ON OFF
15 ON ON ON ON OFF
16 OFF OFF OFF OFF ON
17 ON OFF OFF OFF ON
18 OFF ON OFF OFF ON
19 ON ON OFF OFF ON
20 OFF OFF ON OFF ON
21 ON OFF ON OFF ON
22 OFF ON ON OFF ON
23 ON ON ON OFF ON
24 OFF OFF OFF ON ON
25 ON OFF OFF ON ON
26 OFF ON OFF ON ON
27 ON ON OFF ON ON
28 OFF OFF ON ON ON
29 ON OFF ON ON ON
30 OFF ON ON ON ON

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Addr SW1 SW2 SW3 SW4 SW5
31 ON ON ON ON ON
Table 3. Setting module address in RS485 Modbus network, using DIP switch
4.4 Types of Modbus Functions
There are 4 types of Modbus functions supported by the SfAR modules:
Type Beginning Address Variable Access Modbus Command
1 00001 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
Table 4. Types of Modbus functions supported by the module
4.5 Communication Settings
The data stored in the module's memory is given in the 16-bit registers. The access to
registers is via Modbus RTU or Modbus ASCII.
4.5.1 Default Settings
The default configuration can be restored with the switch SW6.
Baud Rate 19200
Parity No
Data Bits 8
Stop Bits 1
Reply Delay [ms] 0
Modbus Type RTU
Table 5. Default settings
Restore Default Configuration
To restore the default configuration, follow the steps below:
turn the power off;

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turn the switch SW6 on;
turn the power on;
when power and communication LED is lit, turn the switch SW6 off
WARNING! After restoring the default configuration, all values stored in the registers will
be cleared as well.
4.6 Configuration Registers
Modbus Address Decimal Address Hex Address Name Values
40003 2 0x02 Baud Rate 0 – 2400
1 – 4800
2 – 9600
3 – 19200
4 – 38400
5 – 57600
6 – 115200
other – value * 10
40005 4 0x04 Parity 0 – none
1 – odd
2 – even
3 – always 0
4 – always 1
40004 3 0x03 Stop Bits 1 – one stop bit
2 – two stop bits
40004 3 0x03 Data Bits 7 – 7 data bits
8 – 8 data bits
40006 5 0x05 Response Delay Time in ms
40007 6 0x06 Modbus Mode 0 – RTU
1 – ASCII
Table 6. Configuration registers

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5 Indicators
Figure 2. Indicators
Indicator Description
Power Supply The LED indicates that the module is correctly powered
Communication The LED lights up when the unit received the correct packet and sends
the answer
Inputs State The LED indicates that the signal to input is connected
Outputs State The LED indicates that the output is on
Table 7. Description of indicators

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6 Connections
6.1 Block Diagram
Figure 3. Block diagram
6.2 Power Supply Connection
6.2.1 DC Power Connection
Figure 4. DC power connection

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6.2.2 AC Power Connection
Figure 5. AC power connection
6.3 Communication Bus Connection
Figure 6. Communication bus connection
6.4 Connection of Analog Inputs
6.4.1 Connection of Current Measurement
Figure 7. Connection of current measurement

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6.4.2 Connection of Voltage Measurement
Figure 8. Connection of voltage measurement
6.5 Connection of Digital Outputs
6.5.1 Connection of PNP Output
Figure 9. Connection of PNP output
6.5.2 Connection of NPN Output
Figure 10. Connection of NPN output
6.6 Quick Connector
The Quick Connector is an unique feature of modules that allows for quickly connecting a
group of devices with a flat ribbon cable.

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Thanks to this solution, it is enough to the power supply and RS485 communication to
one of the devices in the group, and the others will be powered and communicated with
ribbon cable. The Quick Connector is sufficient to connect up to 10 devices next to each
other. It is important that the various types of modules in the SfAR-S family can be
connected with the ribbon cable.
Figure 11. Quick Connector

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7 Selecting Input Mode
Each input can be used to measure voltage (by default) or current. To change the
operating mode, it is necessary to modify software settings and the position of jumpers
inside the module as shown below.
Figure 12. Jumper setting
7.1 Opening the Case
Figure 13. Opening the case
Remove the catch by pressing it and moving it towards the center of the case. Mind
the spring located under the catch.
Separate parts of the case by gently tilting catches located as shown in the picture
using thin tool.

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8 Analog Filtering
If the measured signal is interrupted, it is possible to eliminate the disruptions by
switching the lowpass filter on. It is possible to configure the filter for all inputs (it is not
possible to enable the filter for only one input). The filter parameter corresponds to the
filter time constant. Step response of the filter is shown in the graph below.
Figure 14. Step response and different coefficients

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9 DIP Switch
Figure 15. DIP switch
Switch Function Description
1 Module address +1 Setting module address from 0 to 31
2 Module address +2
3 Module address +4
4 Module address +8
5 Module address +16
6 Restoring default settings Restoring default settings
Table 8. Description of switches