8-Channel Modbus RTU Latching Relay Module (C) with RS-485 Interface

This 8-channel latching relay module (C) is controlled via RS-485 and uses the Modbus RTU protocol. It features latching relays, meaning the relay states are retained even after power loss - ideal for applications where maintaining output state during outages is important. Housed in a DIN rail-mount ABS enclosure, it's built for quick installation in control cabinets or industrial setups.

Each relay is rated for up to 10A at 250VAC or 30VDC. A dedicated driver chip provides reliable switching, and the flash-on/flash-off function allows relays to activate briefly and then return to their previous state, based on command parameters. The module supports configurable device addresses from 1 to 255 and can be cascaded with multiple units over the RS-485 bus (for longer distances or larger setups, RS-485 repeaters may be needed).

Built-in protection includes unibody power and magnetic isolation, TVS diodes, and a resettable fuse. These help protect against surges, interference, and incorrect wiring. A reverse-proof circuit prevents damage from accidental polarity errors. Three onboard LEDs indicate MCU operation and RS-485 signal transmission.

Note: Power adapter not included (12V DC Barrel Jack supply recommended).

⚠️Electrical Safety Precautions⚠️

• This product should be operated and used by professional electricians or technical personnel. During use, please ensure electrical safety and take protective measures such as anti-leakage and insulation.
• Before installing, maintaining, or replacing relay equipment, make sure to turn off the power and unplug the device.
• Do not attempt to dismantle relay equipment to avoid damaging the device or risking electric shock.
• Please properly install and place the relay equipment. Avoid using it in damp, overly hot, or flammable environments to prevent safety accidents due to improper installation or use.

Features

• Latching relay retains state after power loss
• Configurable device address (1–255); supports cascading on RS-485 bus
• Flash-on/flash-off relay control with timing via command
• Integrated power supply isolation; no separate supply needed for isolated terminal
• Magnetic signal isolation for high reliability and low interference
• Resettable fuse and TVS diode for surge, overcurrent, and electrostatic protection
• Dedicated latching relay driver chip for stable switching
• Reverse-polarity protection circuit
• Relay contact rating: ≤10A at 250VAC or 30VDC
• DIN rail-mount ABS enclosure
• Three LEDs for MCU and RS-485 status indication

Specifications

Power Supply	DC 7~36V
Communication Interface	RS-485
Communication Baudrate	4800, 9600, 19200, 38400, 57600, 115200, 128000, 256000
Default Communication Format	9600, N, 8, 1
Relay Channels	8 Channels
Relay Type	Magnetic latching relay
Contact Form	1NO 1NC
Contact Load	≤10A 250V AC or ≤10A 28V DC
Modbus Protocol	Standard Modbus RTU protocol
RS-485 Address Setting	1~255
Indicator	STA: MCU indicator, keeps flashing when MCU is operating normally TXD: Transmit Data indicator, lights up when transmitting data RXD: Receive Data indicator, lights up when receiving data

Resources

• Product Wiki

Package Contents

• 1x 8-Channel Modbus RTU Latching Relay Module (C) with RS-485 Interface

Power supply not included.