Rockwell Automation 1797-OE8H FLEX Ex HART Analog Modules User Manual - Manual (Page 18)

Publication 1797-6.5.3 - March 2006
1-4 About the FLEX Ex HART Analog Modules
Data Format Alarm Example
In this example, the normal active data range is 4 to 20 mA. The alarms are
generated in three overlapping bands.
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 in a fashion 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.
PHYSICAL INPUT SIGNAL RANGE
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%
Remote Transmitter Error
Up/Down Parameter
Determines Which of These
is Active
Programmable
in 20 0.1 mA
Steps by Error
Level 0.1 mA
Steps
Parameter
100.00% 112.50%
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