Publication 1756-UM001G-EN-P - January 2007
46 Communicate over Networks
HART (Highway
Addressable Remote
Transducer) Protocol
HART is an open protocol designed for process control
instrumentation.
The HART protocol combines digital signals with analog signals to
ready the digital signal for the process variable (PV). The HART
protocol also provides diagnostic data from the transmitter.
HART Protocol Overview
Additional Resources
For additional information, consult these resources:
• FLEX Ex HART Analog Modules User Manual, publication
1797-6.5.3
• Encompass website at http://automation/rockwell/encompass
Functions Required Device
• Acquire data or control application with slow update
requirements, such as a tank farm.
• Does not require external hardware to access HART signal.
• Does not provide a direct connection to asset management
software.
Prosoft interface
MVI56-HART
• Contain analog and HART in one module.
• Does not require external hardware to access HART signal.
• Transmit HART commands as unscheduled messages.
• Support asset management software to HART device
Spectrum analog
I/O modules
• 1756sc-IF8H
• 1756sc-OF8H
• Contain analog and HART in one module.
• Provide instrumentation in hazardous locations (FLEX Ex).
• Transmit HART commands as unscheduled messages.
• Directly connect asset management software to HART devices.
1794 FLEX I/O
modules
• 1794-IE8H
• 1794-OE8H
1797 FLEX Ex I/O
modules
• 1797-IE8H
• 1797-OE8H
ControlLogix Controller
with 1756SC-IF8H or
1756SC-OF8H Modules
HART Field Devices