What is a Hart multiplexer?
What is a HART Multiplexer?
Understanding HART Multiplexer in Process Plants
A HART multiplexer is a communications interface device that allows you to collect digital HART data from several field instruments without disturbing the current 4 20mA control signal. It is used for asset management, diagnostics and predictive maintenance in process industries.
Hundreds of smart transmitters and control valves in major industrial operations communicate via the HART protocol. It is difficult to connect to each instrument individually for diagnostics during plant operation. The solution to this problem is a HART multiplexer, which collects data from many HART devices into a central monitoring system.
How a HART Multiplexer Works
The multiplexer is connected in parallel to existing analog loops and reads digital HART communication data from field equipment. It subsequently sends this information to asset management software, DCS or maintenance workstations.
Main Functions
- Remote diagnostics of devices
- Remote transmitter installation
- Predictive maintenance support
- Monitoring of device status
- Access to the calibration data
- Fault and alarm recognition
Practical Plant Benefits
HART multiplexers reduce the time spent on field maintenance and improve troubleshooting efficiency in refineries, power plants and chemical industries. Engineers in the control room can spot sensor failures, loop faults or valve problems without affecting the plant operation.
The HART multiplexers are especially beneficial in commissioning, shutdown maintenance and reliability improvement programs where continuous monitoring of smart instruments is critical.
Proper integration of HART multiplexers will increase plant visibility, maintenance planning, and overall reliability of the instrumentation system.