32-Ch RS485 Modbus RTU PLC IO Expansion Board | DIN35 Rail
32-Ch RS485 Modbus RTU PLC IO Expansion Board | DIN35 Rail
32-Channel RS485 Modbus RTU Controller with DIN35 Rail Enclosure
Take full control of your automation projects with this compact yet powerful 32-Channel RS485 Modbus RTU PLC IO Expansion Board. Built around the reliable ULN2803A Darlington transistor array, this controller delivers versatile output switching for industrial automation, smart home control, and DIY electronics projects — all housed in a flame-retardant DIN35 rail-mountable enclosure for clean, professional installations.
Key Features
- Wide input voltage range: DC 6.5–30V (compatible with 9V, 12V, and 24V systems)
- 32 independently controllable output channels via ULN2803A Darlington transistors
- 6 versatile command modes: Open, Close, Momentary, Self-locking, Interlock, and Delay (max 255-second delay)
- RS485 Modbus RTU protocol — supports up to 64 devices in parallel for scalable network deployments
- Configurable baud rate: 1200 / 2400 / 4800 / 9600 (default) / 19200 BPS
- Low standby current: 5mA (all channels closed); 57mA (all channels open)
- Max drive current per channel: 300mA
- DIN35 & C45 rail compatible — fits standard industrial enclosures
- Works with serial HyperTerminal, serial assistant software, or Modbus Poll for easy command entry
Specifications
| Parameter | Value |
|---|---|
| Working Voltage | DC 6.5–30V (9V / 12V / 24V) |
| Number of Channels | 32 |
| Max Channel Drive Current | 300mA per channel |
| Standby Current (all off) | 5mA |
| Standby Current (all on) | 57mA |
| Communication Protocol | RS485 Modbus RTU |
| Default Baud Rate | 9600 BPS |
| Max Parallel Devices | 64 |
| PCB Board Size | 100 × 72 × 20 mm |
| With DIN Rail Box Size | 120 × 88 × 42 mm |
| PCB Board Weight | 65g |
| With DIN Rail Box Weight | 144g |
| DIN Rail Box Model | UM72 |
| Rail Box Color | Green |
| Insulation Grade | Flame-retardant V0 |
| Rail Compatibility | DIN35 & C45 |
| Country of Origin | Made in China |
What's in the Box
- 1× DIN35 Guide Rail Box RS485 Modbus RTU 32-Channel Controller
Important Notes
- Due to lighting and screen differences, the item's color may vary slightly from product images.
- Please allow 1–3 cm tolerance due to manual measurement.
Learn More About Industrial Automation Standards
For guidance on electrical safety and industrial control wiring standards, visit the OSHA Electrical Safety Resources.
Frequently Asked Questions
Q: What communication protocol does this 32-channel controller use?
A: This controller uses the RS485 Modbus RTU protocol, a widely adopted industrial standard. It supports up to 64 devices connected in parallel, making it ideal for scalable automation networks. You can send commands via serial HyperTerminal, a serial assistant, or Modbus Poll software.
Q: What voltage does this PLC IO expansion board require?
A: The board operates on a wide DC input range of 6.5V to 30V, making it compatible with common supply voltages including 9V, 12V, and 24V DC systems.
Q: Can I mount this controller on a standard DIN rail?
A: Yes — the included UM72 DIN rail enclosure is compatible with both DIN35 and C45 rails, allowing clean, professional installation inside standard electrical panels and control cabinets.
Q: What are the 6 command modes available on this board?
A: The board supports six Modbus command modes: Open, Close, Momentary, Self-locking, Interlock, and Delay. The Delay mode supports a configurable delay of up to 255 seconds per channel, offering flexible timing control for automation sequences.
Q: How many channels can this board drive, and what is the maximum current per channel?
A: The board provides 32 independently controllable output channels, each capable of driving up to 300mA via the ULN2803A Darlington transistor array — suitable for controlling relays, LEDs, solenoids, and similar loads.