Modbus IO8R-A


8 Opto-Isolated Digital Inputs And 8 Opto-Isolated Digital Relay Outputs
6 12-Bit Analog Inputs, 1 12-Bit Analog Output


The Modbus IO8R-A RTU 8-Channel Relay Module is a communication board designed for industrial control applications. It provides digital and analog input/output capabilities, allowing for monitoring and control of various devices and processes using the Modbus protocol.

Modbus IO8R-A RTU 8-Channel Relay Module:

Digital Input/Output: The module offers 8 digital input (DI) and 8 digital output (DO) channels. The digital inputs can be used to monitor the status of external devices or sensors, while the digital outputs can be used to control external equipment such as relays or actuators.

Analog Input/Output: In addition to digital I/O, the module also includes 6 analog input (AI) channels and 1 analog output (AO) channel. The analog inputs can measure continuous signals from sensors or devices, while the analog output can provide variable control signals to actuators or control systems.

Modbus RTU Communication: The module uses the Modbus RTU protocol for communication over an RS485 interface. This allows for seamless integration with other Modbus-compatible devices such as PLCs, HMIs, or SCADA systems. The Modbus protocol enables reliable and efficient data exchange between devices.

Versatile Control Options: With the combination of digital and analog I/O channels, the module offers flexibility in controlling and monitoring various industrial processes. It can be used in applications such as industrial automation, building management systems, or remote monitoring and control.

Industrial-grade Design: The module is designed to withstand harsh industrial environments. It features a rugged construction and is built to operate reliably in demanding conditions.

Difference Between Modbus Rs485 And Modbus RTU

Modbus is a communication protocol commonly used in industrial automation systems for data exchange between devices. Both Modbus RTU and Modbus RS485 are variations of the Modbus protocol, but they represent different aspects of the communication system.

Modbus RTU

  • Modbus RTU (Remote Terminal Unit) is a communication format within the Modbus protocol.
  • It is a binary-based protocol where data is transmitted in binary format, typically over serial communication such as RS232 or RS485.
  • Modbus RTU uses a master-slave architecture, where a master device initiates communication with one or more slave devices.
  • Data is typically transmitted using a UART (Universal Asynchronous Receiver/Transmitter) communication format with start and stop bits.
  • It uses a compact frame structure with CRC (Cyclic Redundancy Check) error checking for data integrity.
  • Modbus RTU is known for its simplicity, efficiency, and reliability. It is widely used in various industrial applications.

Modbus RS485

  • Modbus RS485 is a physical layer specification used for implementing the Modbus protocol over the RS485 serial communication standard.
  • RS485 is a standard for differential serial communication that allows for long-distance, multi-drop communication between devices.
  • Modbus RS485 specifies the electrical characteristics and wiring configurations for implementing Modbus communication over the RS485 standard.
  • It defines the wiring connections, such as the use of twisted pair cables, termination resistors, and the RS485 communication parameters.
  • Modbus RS485 allows multiple devices to be connected on the same communication bus, with each device having a unique address.
  • RS485 provides the capability for multi-point communication, where one device can transmit data to multiple devices on the same bus.

In summary, Modbus RTU refers to the communication format and protocol used within the Modbus protocol, while Modbus RS485 specifies the physical layer and wiring configurations for implementing Modbus communication over the RS485 standard. Modbus RTU can be implemented over various physical layers, but Modbus RS485 is specifically for RS485 serial communication.

Additional information

Weight 0.5 kg







8 Relay

Analog Inputs


Analog Output



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