Rockwell Automation 1756-OF8H ControlLogix HART Analog I/O Modules - Manual (Page 15)

Rockwell Automation Publication 1756-UM533C-EN-P - February 2011 15
ControlLogix HART Analog I/O Modules Chapter 1
See the figure
(1)
that shows information about the HART protocol.
With the ControlLogix HART analog I/O modules, field device data can be
accessed by both the controller and device maintenance and management
software.
The ControlLogix HART analog I/O modules support Command-response
communication protocol and point-to-point wiring architecture.
(1) The figure is from the HART Communication Protocol Specifications, April, 2001, Revision 6.0, HART
Communication Foundation, All Rights Reserved.
Analog
Signal
The Highway Addressable Remote Transducer
(HART) protocol supports two-way digital
communication, complements traditional
4…20 mA analog signals, and includes the
following features:
·
Predefined commands
- Common practice
- General purpose
- Device specific
·
Large installed base
·
Worldwide support
Analog
Signal
+0.5 mA
0.5 mA
0
1200
Hz
"1" 2200
Hz
"0"
HART Signal
Time (seconds)
0 1 2
20 mA
Analog
Signal
4 mA