HART Modem Development for Communication with Instruments

Abstract

The Large Cryo-Plant and Cryo-system (LCPC) produces liquid helium by using compression and expansion i.e. change of pressure. For this, it has com- pressors and turbines. The Helium plant test facility in LCPC division tests these compressors, turbines, different types of heat exchangers and helium purifiers. The test facility needs many field devices that are sensors for temperature, pressure, ow etc. for testing and diagnosis. Data gathered from these field devices needs to be sent to control system. The project was focused to achieve the goal of accomplishing Highway Address- able Remote Transducer (HART) protocol based system hardware to acquire data from the field devices and forward to the control system of the test facility. HART is a communication protocol widely used in the field of industrial automation because of its ease of usage and compatibility with analog and digital devices. The work was carried out to design and implement a HART modem which takes inputs from the field devices and sends data to the control system using serial communication. Current system coverts data acquired from field sensors into digital data and then transmits to control system via Ethernet. Implementation of HART removed the need of digital data conversion and sends data directly.