1. This design is a relay for industrial application scenarios. It uses Modbus RTU protocol control and RS485 signal as the transmission mode. It supports multiple devices controlled by the same host. It can be applied to industrial automation. With ABS shell and DIN rail mounting, it is suitable for real-world environments. 2. The board is equipped with a stable 8-bit MCU and SP3485 level conversion chip. 3. Wiring instructions: The relay can be assigned an address on the RS485 bus, ranging from 1 to 255. Corresponding commands can be sent to the relay’s address to control its output state, enabling opening or closing of connected circuits. 4. Note: When the relay is energized, the COM terminal connects to the NO terminal and disconnects from the NC terminal. When the relay is de-energized or unpowered, the COM terminal connects to the NC terminal and disconnects from the NO terminal. Power supply voltage: 5–32 V (6 V recommended for optimal stability) Communication protocol: Standard Modbus RTU protocol Communication interface: RS485 interface with 120 Ω termination resistor dip switch Baud rate: 4800 / 9600 / 19200 / 38400 bps (default: 9600 bps); supports power-off parameter retention Output signal: Relay switch signal Product appearance and printed text may vary slightly between batches; such variations do not affect functionality. Color: As shown in image Material: ABS Package Contents: 1 × 2-channel relay Note: Light reflection and display differences may cause slight color variation between the image and the actual product. Measurement tolerance: ±1–3 cm.