MD-H485 (MODPORT Header module)

This product line is a field I/O solution designed for use with ComfilePi, CPCV series, and as an I/O expansion system for ComfileHMI. It provides a simple and reliable way to extend digital and analog I/O in industrial automation systems without additional programming effort.

Each module operates as a Modbus RTU slave over RS-485. No firmware development is required. Simply connect the modules via RS-485, assign a Modbus slave address to each module, and the system is immediately ready for operation. This approach significantly reduces setup time and makes the system easy to scale.

A wide variety of I/O modules is available, allowing flexible system configuration to match the exact requirements of your application. From digital inputs and outputs to high-resolution analog and temperature inputs, the MODPORT series covers most common industrial I/O needs.

• MD-H485 – RS-485 header module
• MD-DIDC8 – DC 24 V digital input module (8 channels)
• MD-DOSO8 – DC source output module (8 channels)
• MD-DOSI8 – DC sink output module (8 channels)
• MD-DORL8 – Relay output module (8 channels)
• MD-ADIN4 – 13.3-bit analog input module (4 channels, 0–10 V / 1–5 V / 4–20 mA)
• MD-HADIN4 – 16.6-bit high-resolution analog input module (4 channels, 0–10 V / 1–5 V / 4–20 mA)
• MD-THRT4 – PT100 RTD temperature input module (4 channels)
• MD-DAOUT2 – Analog output module (2 channels, 0–10 V / 0–5 V)

Note: At least one slot board must be purchased separately to install and operate the MODPORT modules.

FAQ

Q: Can’t I connect sensors directly to a PC?

A: In general, no. Standard PCs—and most HMI devices as well—do not have direct industrial I/O built in. The reason is straightforward. User requirements vary widely: different signal types, voltage levels, isolation needs, response times, and environmental conditions. If PC-class hardware tried to include all of these options, it would result in hundreds of different hardware variants, which is simply impractical.

That’s why a separate product category called field I/O exists.

Field I/O devices are designed specifically to handle real-world signals from sensors and actuators, while the PC or HMI focuses on processing, visualization, and control logic. This separation allows systems to remain flexible, scalable, and much easier to design and maintain. In short, PCs are not meant to talk to sensors directly—that’s exactly the role field I/O was created to fill.

Q: This product uses RS-485. Does it support other interfaces, such as Ethernet or USB?

A: No, this product supports RS-485 only. Other interfaces such as Ethernet or USB are widely available in many third-party products. This model is intentionally focused on RS-485, which remains a proven and widely used interface in industrial environments.

Dimmension