An RS485-controlled industrial I/O module with 8 isolated digital inputs and 8 open-drain digital outputs, communicating via the Modbus RTU protocol. Multiple protection layers — power isolation, magnetic isolation, TVS diode, and resettable fuse — ensure stable and reliable operation in demanding environments.

The rail-mount ABS enclosure supports easy installation and stacking for expanded systems. Compatible with Raspberry Pi, Arduino, and STM32 via RS485 CAN HATs or shields.

Key Features

• RS485 Modbus RTU – Configurable addresses (1–255) with cascading support
• 8 Digital Inputs – 5–36 V, passive/active, NPN/PNP, optocoupler-isolated
• 8 Digital Outputs – Open-drain with Darlington transistors, up to 500 mA sinking per channel
• DI/DO Linkage – Input-to-output linking and toggle control via Modbus commands
• Flash On/Off – Timed output control with built-in flyback diode protection
• Multi-Layer Protection – Power isolation, magnetic isolation, TVS diode, resettable fuse, and ESD protection
• LED Indicators – STA (MCU status), TXD, RXD, plus individual input/output status LEDs
• Rail-Mount Enclosure – Industrial ABS housing, stackable for expansion

Specifications

• Power Supply – 7–36 V DC
• Communication – RS485 (Modbus RTU)
• Baud Rate Options – 4 800, 9 600, 19 200, 38 400, 57 600, 115 200, 128 000, 256 000 (default: 9 600, N, 8, 1)
• Digital Inputs – 8 channels, 5–36 V
• Digital Outputs – 8 channels, 5–36 V, max 500 mA per channel
• Address Range – 1–255

Compatibility

• Raspberry Pi – Via RS485 CAN HAT (Python)
• STM32 – Via RS485 CAN Shield (C)
• Arduino – Via RS485 CAN Shield (Arduino IDE)
• PC – Windows, Mac, Linux, and Android via FTDI-based USB-to-RS485 adaptor

Ideal For

• Industrial automation and process control
• Smart home relay and actuator control
• Remote monitoring and data acquisition
• Multi-node RS485 sensor/actuator networks

Resources

• Waveshare Wiki – Modbus RTU IO 8CH