Modbus SFAR-S-8AI2DO User manual

SFAR-S-8AI2DO
User Manual
Expansion Module –8 Analog Inputs,
2 Digital Outputs
Global Control 5 Sp. z o.o.
Warsaw, Poland
www.gc5.pl

SFAR-S-8AI2DO User Manual
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Table of contents
2.1. Purpose and description of the module....................................................................... 4
2.2. Technical specifications ................................................................................................. 5
2.3. Dimensions of the product ............................................................................................. 6
3.1. Grounding and shielding ................................................................................................. 6
3.2. Network termination........................................................................................................ 7
3.3. Setting Module Address in RS485 Modbus Network................................................ 7
3.4. Types of Modbus registers............................................................................................. 8
3.5. Communication settings ................................................................................................ 8
3.5.1. Default settings...................................................................................................... 8
3.5.2. Restore the default configuration....................................................................... 8
3.5.3. Configuration registers......................................................................................... 9
5.1. Block diagram .................................................................................................................10
5.2. Connection of analog inputs ........................................................................................10
5.2.1. Connection of current measurement...............................................................10
5.2.2. Connection of voltage measurement .............................................................. 11
5.3. Connection of digital outputs.......................................................................................11
5.3.1. Connection of PNP output ................................................................................. 11
5.3.2. Connection of NPN output................................................................................. 11
5.4. Quick Connect.................................................................................................................12
10.1. Registered access ...................................................................................................15
10.2. Bit access..................................................................................................................17

SFAR-S-8AI2DO User Manual
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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.
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
1. Refer to this manual before the first use.
2. Make sure that all cables are connected properly before the first use.
3. Please ensure proper working conditions, according to the device specifications
(e.g., supply voltage, temperature, maximum power consumption)
4. Turn the power supply off before making any modifications to wiring connections, turn
off the power supply
2. Module features
2.1. Purpose and description of the module
SFAR-S-8AI2DO module allows measurement of voltages and currents. Values are read via
RS485 (Modbus), so we can easily integrate the module 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 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. You can also
change the parameters using the Modbus protocol.

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2.2. Technical specifications
Power Supply
Voltage
10-38 V DC; 10-28 V AC
Power consumption1
2.4 W @ 24 V DC
3 VA @ 24 V AC
Isolation
Isolation between power supply and I/O
1000 V DC
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
Max voltage
1 mV
Absolute maximum input current
± 35 mA
Current input impedance
100 Ω
Current measurement accuracy
± 0.2 %
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
Digital outputs
Maximum current and voltage
500 mA / 55 V
Temperature
Work
-20°C - +65°C
Storage
-40°C - +85°C
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
Length
101 mm
Width
22.6 mm
Interface
RS485
Up to 128 devices
1
Power consumption with active Modbus transmission, all outputs on and high state on all inputs

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Table 1 - Technical specifications
2.3. Dimensions of the product
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 IOs
are at the bottom and top of the module. USB connector configuration and indicators are
located on the front of the module.
3. Configurating of the communication
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.
Picture 1 - Dimensions of the product

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3.2. 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 equal to its characteristic impedance. Both ends
must be terminated since the direction of propagation is bi-directional. In the case of RS485
twisted pair cable this termination is typically 120 Ω.
3.3. 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
SW5
SW4
SW3
SW2
SW1
0
OFF
OFF
OFF
OFF
OFF
1
OFF
OFF
OFF
OFF
ON
2
OFF
OFF
OFF
ON
OFF
3
OFF
OFF
OFF
ON
ON
4
OFF
OFF
ON
OFF
OFF
5
OFF
OFF
ON
OFF
ON
6
OFF
OFF
ON
ON
OFF
7
OFF
OFF
ON
ON
ON
8
OFF
ON
OFF
OFF
OFF
9
OFF
ON
OFF
OFF
ON
10
OFF
ON
OFF
ON
OFF
11
OFF
ON
OFF
ON
ON
12
OFF
ON
ON
OFF
OFF
13
OFF
ON
ON
OFF
ON
14
OFF
ON
ON
ON
OFF
15
OFF
ON
ON
ON
ON
Addr
SW5
SW4
SW3
SW2
SW1
16
ON
OFF
OFF
OFF
OFF
17
ON
OFF
OFF
OFF
ON
18
ON
OFF
OFF
ON
OFF
19
ON
OFF
OFF
ON
ON
20
ON
OFF
ON
OFF
OFF
21
ON
OFF
ON
OFF
ON
22
ON
OFF
ON
ON
OFF
23
ON
OFF
ON
ON
ON
24
ON
ON
OFF
OFF
OFF
25
ON
ON
OFF
OFF
ON
26
ON
ON
OFF
ON
OFF
27
ON
ON
OFF
ON
ON
28
ON
ON
ON
OFF
OFF
29
ON
ON
ON
OFF
ON
30
ON
ON
ON
ON
OFF
31
ON
ON
ON
ON
ON
Table 2 – Setting Module Address in RS 485 Modbus Network

3.4. Types of Modbus registers
There are 4 types of variables available in the module
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 2 - Types of variables
3.5. Communication settings
The data stored in the module’s memory is given in the 16-bit registers. The access to
registers happens via Modbus RTU or Modbus ASCII.
3.5.1. Default settings
You can restore the default configuration by the switch SW6 (see 3.5.2 - Restore the default
configuration)
Table 3 - Default settings
3.5.2. Restore the default configuration
To restore the default configuration:
•turn the power off
•turn the switch SW6 on
•turn the power on
•when power and communication LED flash turn the switch SW6 off
WARNING! After restoring the default configuration all values stored in the registers will be
Baud rate
19200
Parity
No
Data bits
8
Stop bits
1
Reply Delay [ms]
0
Modbus Type
RTU

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cleared as well.
3.5.3. Configuration registers
Modbus
Dec
Hex
Name
Values
Address
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 1
4 – 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 bits
8 – 8 data bits
40006
5
0x05
Response delay
Time in ms
40007
6
0x06
Modbus Mode
0 – RTU
1 – ASCII
Table 4 - Configuration registers
4. Indicators
Picture 2 - Indicators

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5. Module connection
5.1. Block diagram
5.2. Connection of analog inputs
5.2.1. Connection of current measurement
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.
Inputs state
LED indicates that the signal to input is connected.
Outputs state
LED indicates that the output is on.
Table 5 - Description of indicators
Picture 3 – Block diagram
Picture 4 – Connection of current measurement