F&F MR-DI-4 LO Digital Input Expansion Module, 4 Inputs 6-30V AC/DC, MODBUS RTU, 9-30V DC

The F&F MR-DI-4 LO is a professional digital input expansion module engineered for industrial automation and building management systems. This device provides a reliable interface for monitoring external signals, featuring four independent digital inputs that support a wide voltage range of 6-30V AC/DC. Designed for seamless connectivity, the module utilizes the industry-standard MODBUS RTU communication protocol, allowing it to integrate effortlessly with various PLC controllers, SCADA systems, and centralized monitoring units.

Advantages

This expansion module offers high versatility by accepting both AC and DC voltage signals, which simplifies installation in diverse electrical environments. The use of the MODBUS RTU protocol ensures stable and high-speed data transmission, making it an ideal choice for complex automation networks. Its compact design and wide power supply range of 9-30V DC allow for flexible deployment in control cabinets where space and power options may be limited. The device is built to maintain consistent performance in demanding industrial conditions, ensuring accurate signal acquisition and reliable system feedback.

Suitable for

• Industrial automation systems
• Building management and smart home control
• Monitoring of sensors and limit switches
• Integration with PLC and SCADA controllers
• Remote status reporting of electrical circuits

When it may not be suitable

This module is not intended for switching high-power electrical loads directly, as it is designed exclusively for signal acquisition and monitoring purposes. It is also not suitable for environments requiring specialized communication protocols other than MODBUS RTU.

Key specifications

• Number of digital inputs: 4
• Input voltage range: 6-30V AC/DC
• Communication protocol: MODBUS RTU
• Power supply voltage: 9-30V DC
• Mounting type: DIN rail

How to use

Installation should be performed by a qualified professional in accordance with local electrical regulations. Mount the module on a standard DIN rail within a protected control cabinet. Connect the power supply to the designated terminals, ensuring the voltage is within the 9-30V DC range. Wire the digital input signals to the corresponding input terminals, respecting the 6-30V AC/DC limit. Once physically connected, configure the module within your MODBUS master device by setting the appropriate communication parameters such as address, baud rate, and parity to establish a successful data link.

What to consider before purchase

• Ensure your control system supports the MODBUS RTU protocol.
• Verify that your input signals fall within the 6-30V AC/DC range.
• Confirm that a 9-30V DC power supply is available for the module.
• Check the available space on the DIN rail in your control cabinet.

Usage recommendations

Always ensure that the input signal voltage does not exceed the specified maximum limits to prevent damage to the internal circuitry. Regularly verify the integrity of the communication wiring to maintain stable MODBUS RTU connectivity.