Resources:
Wiki: www.waveshare.com/wiki/Modbus_RTU_Relay_32CH
Modbus RTU 32-Ch Relay Module, RS485 Interface, With Multiple Isolation Protection Circuits, Industrial-Grade, Rail-Mount Case
The Modbus RTU 32-Channel RS485 Interface Relay Module is a high-performance industrial-grade relay control board designed for automation systems, smart factories, and industrial monitoring applications. Featuring 32 independent relay channels, each with optocoupler isolation, this module provides reliable switching control for both AC and DC loads. The system communicates via the RS485 bus using the Modbus RTU protocol, ensuring fast, stable, and interference-resistant operation across long distances. Built with robust electrical protection circuits such as power isolation, magnetic isolation, resettable fuse, and TVS diode, this module is engineered for demanding environments. The onboard voltage regulator supports a wide 7~36V DC input range, while the unibody isolated design provides safe and stable operation without requiring an additional power supply for the relay terminal.
Each relay is driven by a dedicated driver chip with freewheeling diode protection to prevent damage from voltage spikes, supporting a maximum contact rating of 10A at 250VAC/30VDC. The module includes flash-on/flash-off functionality, allowing relays to toggle automatically for preset durations, making it ideal for time-based or sequential control applications. The rail-mount ABS enclosure provides easy and secure installation, while LED indicators for MCU and communication status make system diagnostics straightforward. With a configurable Modbus address (1–255) and multi-device cascading support, this relay module is perfectly suited for large-scale industrial automation networks.
Key Features
- 32 Independent Relay Channels:
Supports switching of high-current loads up to 10A (250VAC/30VDC) with full isolation.
- Modbus RTU over RS485 Communication:
Standard Modbus RTU protocol enables easy integration with PLCs, HMIs, and SCADA systems.
- Wide Input Voltage Range:
Operates from 7V to 36V DC with onboard voltage regulator for consistent performance.
- Full Electrical Isolation:
Built-in power and magnetic isolation ensures reliable, noise-free communication and operation.
- Protection Circuits Built-In:
Resettable fuse and TVS diode offer over-voltage, over-current, lightning, and ESD protection.
- Optocoupler Isolation:
Prevents interference between the relay control circuit and high-voltage loads.
- Dedicated Relay Driver Chip:
Ensures powerful, stable drive with freewheeling diode protection for voltage spike suppression.
- Flash-On / Flash-Off Function:
Allows automatic timed activation and deactivation via Modbus command.
- Cascadable Configuration:
Supports up to 255 devices connected via RS485 bus for large-scale systems.
- Industrial-Grade Design:
Enclosed in a rail-mounted ABS case for easy installation and long-term durability.
- LED Indicators:
Displays MCU activity, RS485 transmission, and relay status for real-time monitoring.
RS485 32-Ch Relay Module
Onboard Multiple Isolation Protection Circuit
Relay Connection
The contact rating of the onboard relay is up to 10A at 250VAC/30VDC.
Directly managing 220VAC home appliances or gadgets below 30VDC.
Dimensions
Package Content:
- Modbus RTU Relay 32CHx1
