DC 12V/24V 12DI 12DO RS485 Modbus RTU Relay IO Board Module
DC 12V/24V 12DI 12DO RS485 Modbus RTU Relay IO Board Module
DC 12V/24V 12DI 12DO RS485 IO Board — Modbus RTU Relay Module with Opto-Isolated NPN Inputs
Take full control of your automation projects with this robust Modbus RTU Relay IO Board. Designed for DC 12V or 24V systems, this module features 12 optically isolated NPN inputs and 12 upgraded relay outputs, making it ideal for PLC expansion, smart home automation, security monitoring, LED lamp drivers, and more. Built with TVS anti-surge protection and a hardware reset function, it delivers reliable, long-lasting performance in demanding environments. Made in Mainland China.
Key Features
- Dual Voltage Support: Compatible with DC 12V and DC 24V systems.
- 12 Opto-Isolated NPN Inputs: Photoelectric isolation protects your controller from voltage spikes and signal noise.
- 12 Upgraded Relay Outputs: Enhanced durability with a maximum load of 10A/250VAC, 10A/30VDC.
- Modbus RTU Protocol: Supports standard function codes — Write: 05/06/15/16 | Read: 01/02/03.
- Flexible I/O Association Modes: Self-locking (default), Interlocking, Momentary, and Output=Input modes configurable via command.
- Multi-Device Support: Connect up to 64 devices in parallel under Modbus RTU command mode.
- Configurable Baud Rates: Default 9600 BPS; selectable at 2400, 4800, 9600, 19200, 38400, 57600, and 115200 BPS.
- Parity Options: None, Even, or Odd parity supported.
- TVS Anti-Surge Protection: Guards the board against transient voltage events.
- Hardware Reset: Restore factory settings instantly via the RESET jumper.
- DIN Rail Compatible: Fits standard DIN35 and C45 rails with the included UM72 DIN rail box.
- Adjustable Response Timing: Data send/return delay configurable up to 1000ms.
Specifications
| Input Voltage | DC 12V or DC 24V |
| Digital Inputs | 12 x Opto-isolated NPN (low-level active) |
| Relay Outputs | 12 x Relay output |
| Max Relay Load | 10A/250VAC, 10A/125VAC, 10A/30VDC, 10A/28VDC, 10A/12VDC |
| Communication | RS485, Modbus RTU |
| Default Baud Rate | 9600 BPS |
| Max Parallel Devices | 64 |
| Standby Current | 14mA (all relays closed) |
| PCB Dimensions | 188 × 72 × 12 mm |
| With DIN Rail Box | 190 × 82 × 40 mm |
| PCB Weight | 206g |
| Weight with Box | 330g |
| DIN Rail Box Model | UM72, Grey, Flame-Retardant V0 Grade |
| Country of Origin | Mainland China |
Common Applications
- PLC RS485 IO expansion boards
- Smart home & home automation systems
- PTZ camera and security monitoring control
- Access identification systems
- LED lamp driver switching
- Automated curtain and blind control
- Battery test and detection systems
What's in the Box
- 1 × Modbus RTU Relay Module (12DI/12DO RS485 IO Board)
Note: Due to lighting and screen differences, the item's color may appear slightly different from the pictures. Please allow 1–3 cm differences due to manual measurement.
For further information on industrial automation safety and electrical standards, visit the OSHA Electrical Safety Resource.
Frequently Asked Questions
Q: What communication protocol does this RS485 relay module support?
A: This module supports the standard Modbus RTU protocol via RS485 communication. It is compatible with function codes for reading (01, 02, 03) and writing (05, 06, 15, 16), and can interface directly with PLCs, industrial computers, or any Modbus RTU master using a serial terminal or Modbus Poll software.
Q: How many devices can be connected in parallel using this Modbus RTU relay board?
A: Under Modbus RTU command mode, this IO board supports up to 64 devices connected in parallel on a single RS485 bus, making it well-suited for scalable industrial automation and smart home installations.
Q: Can I configure the input-output relationship modes on this relay module?
A: Yes. The module supports multiple configurable I/O association modes via command, including Self-locking (default), Interlocking, Momentary, and Output=Input. You can also adjust the baud rate, parity settings, and data response timing to suit your specific control application.
Q: Is the DIN rail mounting box included with this module?
A: The DIN rail box (Model UM72, grey, flame-retardant V0 grade) is available as a bundle option with the PCB board. The box fits DIN35 and C45 standard rails and accommodates the 188mm PCB. Please verify the variant selected at checkout includes the DIN rail box if required.