Industrial Modbus RTU 8-ch Relay Module - Waveshare

This is an industrial 8-ch relay module controlled via RS485 bus, utilizing Modbus RTU protocol. It features embedded protection circuits such as power isolation, ADI magnetical isolation, and TVS diode, etc. It also comes with an ABS enclosure.

The Modbus RTU Relay is very easy to use. Due to its fast communication, stability, reliability, and safety, it is an ideal choice for industrial control equipments and/or applications with high communication requirement.

Specifications :
Power supply voltage: 5V
Communication interface: RS485
Baudrate: 4800, 9600, 19200, 38400, 57600, 115200, 128000, 256000
Default communication format: 9600, N, 8, 1
Relay channels: 8
Contact form: 1NO 1NC
Communication protocol: Standard Modbus RTU protocol
RS485 address: 1~255
RS485 terminal protection: 600W lightning-proof and surge-suppress, 15KV ESD protection (reserved 120R balancing resistor solder pads)
LED indicators:
STA: MCU indicator, keep flashing when the MCU normally working
TXD: TX indicator, light up when sending data
RXD: RX indicator, light up when receiving data


sources : http://www.waveshare.com/wiki/Modbus_RTU_Relay