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

This 8-channel relay module (E) is controlled via RS-485 using the Modbus RTU protocol. It’s housed in a DIN rail-mountable ABS enclosure and is designed for demanding control environments where reliable high-current switching and communication stability are essential. Each channel supports a contact rating of up to 30A at 250V AC or 28V DC. Onboard screw terminals with protective covers simplify wiring for heavy-duty applications. The module also features a configurable device address range (1–255), allowing multiple devices to be cascaded on a single RS-485 bus. Built-in protection includes power isolation, ADI magnetic isolation for signal lines, a resettable fuse, and a TVS diode to guard against surges and spikes. It also features optocoupler isolation to reduce interference from high-voltage circuits and uses a dedicated driver chip with flyback diode protection for more stable relay performance. A reverse-proof circuit protects against accidental incorrect connections. Power is supplied via an onboard voltage regulator, supporting a wide 7–36V DC input range. The design also includes an integrated unibody power isolation system, requiring no extra supply for the isolated terminals. LED indicators are included for MCU and signal status monitoring, and flash-on/flash-off behaviour can be configured by passing arguments to control commands. 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

* Configurable device address (1–255); supports cascading multiple devices on the RS-485 bus

* Flash-on/flash-off relay control via command with timing support

* Wide voltage input range: 7V–36V DC

* Integrated power supply isolation - no separate supply required for isolated terminal

* ADI magnetic isolation for improved signal reliability and interference resistance

* Resettable fuse and TVS diode for surge, overcurrent, and electrostatic protection

* Optocoupler isolation to reduce high-voltage interference

* Relay driver chip with built-in flyback diode

* Reverse-polarity protection circuit

* Relay contact rating: ≤30A at 250V AC or ≤30A at 28V DC

* DIN rail-mount ABS enclosure

* Three status LEDs: MCU activity, transmit, and receive indicators

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 High-power relay

Contact Form 1NO 1NC

Contact Load ≤30A 250V AC or ≤30A 28V DC

Modbus Protocol Standard Modbus RTU protocol

RS-485 Address Setting 1~255

Indicator STA: MCU indicator, keeps flashing when MCU is working 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 Relay Module (E) with RS-485 Interface

Power adapter not included