32-Channel RS485 Relay Module Modbus RTU PLC IO Board DIN Rail
32-Channel RS485 Relay Module Modbus RTU PLC IO Board DIN Rail
32-Channel RS485 Relay Module — Modbus RTU | DC 12/24V | DIN Rail Enclosure
Take full control of your automation projects with this powerful 32-Channel RS485 Relay Module (RYR432D). Designed for engineers, integrators, and makers alike, this multifunction Modbus RTU switch board delivers industrial-grade relay switching over a standard RS485 serial interface — all in a compact DIN Rail-mountable enclosure. Whether you're expanding a PLC I/O system, building a smart home setup, or managing a large-scale industrial automation network, this board is engineered to deliver reliable, flexible, and scalable performance.
Made in Mainland China.
Key Features
- 32 Independent Relay Channels — switch up to 32 separate loads simultaneously or independently
- DC 12V / 24V Dual Voltage Support — flexible power input for a wide range of control panels and installations
- Modbus RTU Protocol — supports Write commands 05/06/15/16 and Read commands 01/03 for seamless PLC and SCADA integration
- 8 Powerful Control Modes: ON, OFF, Momentary, Self-locking, Interlock, Delay (up to 255 seconds), Open All, Close All
- RS485 Communication — industry-standard serial interface for long-distance, noise-immune data transmission
- Configurable via DIP Switches — set Slave ID (1–63) and baud rate (9600 / 19200 / 38400 / 115200 BPS) without software
- Selectable Parity: None (Default) / Even / Odd
- 20A Board Rating with per-channel load capacity of 7A @ 120VAC or 10A @ 28VDC
- DIN Rail Box Included — snap into standard DIN rail for clean, professional panel installation
- Compatible with serial HyperTerminal, serial assistants, and Modbus Poll software
Technical Specifications
| Working Voltage | DC 12V / 24V |
| Channels | 32 |
| Standby Current | 5 mA (all relays off) |
| 1 Relay ON Current | 49 mA |
| All Relays ON Current | ~1500 mA |
| Max Relay Load | 7A @ 120VAC / 10A @ 28VDC |
| Communication | RS485, Modbus RTU |
| Baud Rate | 9600 / 19200 / 38400 / 115200 BPS |
| Slave ID Range | 1–63 (DIP switch configurable) |
| Max Delay | 255 seconds |
| Board Size | 224 × 90 × 16 mm |
| With DIN Box Size | 228 × 106 × 36 mm |
| Board Weight | 330 g |
| With DIN Box Weight | 447 g |
| EU LVD Voltage Class | Below 50VAC or 75VDC (Low Voltage) |
Typical Applications
- PLC I/O Expansion Boards
- HMI Configuration Software Integration
- Smart Home & Home Automation Systems
- Industrial Automation & Process Control
- PTZ CCTV Camera Control
- Security Monitoring Systems
- Access & Identification Systems
- Automated Curtain & Blind Control
- LED Lighting Control
- Agricultural Water Supply Systems
- Stirring & Mixing Systems
Package Contents
- 1× RYR432D 32-Channel RS485 Relay Module (with DIN Rail Box)
Note: Slight color variations may occur due to monitor/screen differences. Please allow ±1–10 mm measurement tolerance due to manual measurement.
For guidance on safe electrical installation practices and control panel wiring standards, refer to OSHA Electrical Safety Guidelines.
Frequently Asked Questions
Q: What communication protocol does the RYR432D 32-Channel Relay Module use?
A: The RYR432D uses the Modbus RTU protocol over an RS485 serial interface. It supports Write commands 05, 06, 15, and 16, and Read commands 01 and 03. You can control it via any Modbus RTU master device, PLC, HMI, serial HyperTerminal, serial assistant software, or tools like Modbus Poll.
Q: How do I set the Slave ID and baud rate on this relay module?
A: Both the Slave ID (1–63) and baud rate (9600 / 19200 / 38400 / 115200 BPS) are configured directly via the onboard DIP switches — no software configuration is required. Parity (None / Even / Odd) can also be set via DIP switches.
Q: What is the maximum load each relay channel can handle?
A: Each relay channel can handle up to 7A at 120VAC or 10A at 28VDC. The board has an overall rating of 20A. Always ensure your connected loads stay within these limits for safe and reliable operation.
Q: Does the relay module come with a DIN Rail enclosure?
A: Yes! The RYR432D comes with a DIN Rail Box included in the package, making it easy to mount neatly inside a standard electrical control panel or enclosure. The assembled dimensions with the box are 228 × 106 × 36 mm.
Q: What control modes are available for the relay channels?
A: The module supports 8 control modes: ON, OFF, Momentary, Self-locking, Interlock, Delay (up to 255 seconds), Open All, and Close All — giving you maximum flexibility for a wide range of automation scenarios.