USB HART Modem

Product description

The HM1-UD is a single-channel USB HART modem. It connects a PC or laptop to HART field instruments so that standard asset-management software can configure, calibrate, maintain and diagnose them — over a simple USB connection, with no separate power supply and no serial port required.

A supplied driver creates a virtual serial (COM) port that behaves exactly like a conventional serial port, so any HART-capable device-management package can use it. Because the connection is USB, the HM1-UD suits portable engineering tools — laptops and tablets that no longer provide a built-in serial interface.

Connecting to a HART loop

Two flexible flying leads with grabber clips connect the modem across the HART loop — either across the loop sense resistor or directly across the instrument. The connection is polarity-independent, and the loop interface is fully isolated from the PC. A HART signal needs a loop load of roughly 250 Ω; on a live 4–20 mA loop this is usually already present.

Features

• Standard COM-port interface — works with any DTM/DD-based host tool.
• Point-to-point and multi-drop — acts as primary or secondary HART master.
• USB bus-powered — data and power on one connection; nothing else to plug in.
• Fully isolated loop (2500 V) and polarity-independent connection.
• Portable USB-stick form factor with grabber-clip flying leads; USB extension lead supported.
• Cross-platform drivers — produced for Windows, macOS and Linux.

Technical data

Compliance: CE (EN ISO 17050-1:2004) · FCC Part 15 (Class A) · ICES-003.

Product support

For assistance, raise a support ticket at the address below and quote the model HM1-UD, your operating system and the device-management software you are using. The support site also hosts the modem driver, the User Manual and the Quick Start Guide.