P-AL
Alarm Type 2:
P-AH
Alarm Type 1:
This function sets the control action for
the optional alarm output relays. The CN4520, CN4620,
CN4720 comes with two relays while the CN4420
comes with one. They can be programmed for
absolute, deviation, combination, or zone alarm config-
uration. The high and low alarm setpoints are set with
primary menu parameters AH and AL. The absolute
alarm configurations are independent of main setpoint.
The alarm output relays are energized when the
process variable exceeds the alarm setpoint, an
absolute value. The deviation alarm configuration is
main setpoint tracking. The alarm output relays are
energized when the process variable exceeds the
main setpoint by a deviation value set by AL or AH.
The combination alarm configurations are a mixture of
both the deviation and absolute value settings for the
high and low alarms. With zone alarm configurations
the alarm output is energized between the range set
by AL and AH.
One of the alarm types is Alarm with Hold. In this case
the alarm is not turned on the first time the measured
value is in the alarm band. Instead it turns on only
when the measured value goes out of the band and
enters it again. This type is useful when using devia-
tion alarm with step type input.
Enter the code for P-AH and P-AL from the Table of
Alarm Action Type Codes on page 36.
Note 1: A change of alarm action type can cause the
alarm set value to change, but this is not a malfunction.
Note 2: After the alarm type is changed, turn off the
power to the unit once.
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