Rockwell Automation 1794-OF8IH FLEX Isolated Input/Output HART Analog Modules - Manual (Page 16)

Publication 1794-UM065B-EN-E - September 2010
4 About the FLEX I/O HART Analog Module
Data Format Alarm Example
In this example, the normal active data range is 4…20 mA. The alarms are
generated in three overlapping bands.
Physical Input Signal Ranges
Overrange Alarm
The overrange alarm notifies you when module input is overrange. When the
input signal exceeds 100% (20 mA), an Overrange Alarm is generated.
This alarm stays active at any value above 100% of range and is always enabled
by the module.
Underrange Alarm
The underrange alarm works converse to the overrange. This feature notifies
you when the input signal falls underrange. If the input signal falls below
0% (4 mA), an Underrange Alarm is generated.
This alarm stays active at any value below 0% of range and is always enabled by
the module.
Remote Fault Alarm
The remote fault alarm is intended for use with remote transmitter loops.
For example, the remote transmitter may be measuring temperature and
converting it to a standard mA signal. In such a loop, though, the input module
cannot determine the state of the loop on the far side of the transmitter.
0 mA 4 mA 20 mA 22 mA
Remote Fault Remote Fault
Local
Fault Local
Fault
Underrange Overrange
Programmable
in 20 0.1 mA
steps by Error
Level 0.1 mA
Steps
parameter
-12.50%
0.00% -25.00% Programmable
in 20 0.1 mA
steps by Error
Level 0.1 mA
Steps
parameter 100.00% 112.50%
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