Purpose and description of the module
The SfAR-S-8DI8RO module is an innovative device that provides a simple and cost-effective extension of the number of lines of input and output in popular PLCs.
The module has 8 digital inputs with configurable timer/counter option and 8 relay outputs. In addition, terminals IN1 and IN2, and IN3 and IN4 can be used to connect two encoders. All inputs are isolated from the logic using optocouplers. Each channel can be individually configured in one of several modes.
The 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, power supply, and communication, 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.
10-38 V DC; 10-28 V AC
Power consumption (with active Modbus transmission and high state on all outputs)
3 W at 24 V DC
4.8 VA at 24 V AC
No of inputs
Low State „0"
High State „1"
PNP lub NPN
No of outputs
The maximum current and voltage (resistive load)
3 A 230 V AC
3 A 30 V DC
No. of counters
1 kHz (max)
500 μs (min)
-10 °C to +50°C (14°F to 122°F)
-40 °C to +85°C (-40°F to 185°F)
119.1 mm (4.689 in)
110.9 mm (4.366 in)
22.7 mm (0.894 in)
Up to 128 devices
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.