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PD6210 Analog Input Batch Controller Instruction Manual
33
Programming Alarm Set and Reset Points
High alarm indication: program set point above reset point.
Low alarm indication: program set point below reset point.
The deadband is determined by the difference between set and reset points. Minimum deadband is one
display count. If the set and reset points are programmed with the same value, the relay will reset one
count below the set point.
Note: Changes are not saved until the reset point has been accepted.
Setting Fail-Safe Operation
In fail-safe mode of operation, the relay coil is energized when the process variable is within safe limits and
the relay coil is de-energized when the alarm condition exists. The fail-safe operation is set independently
for each relay. Select
on
to enable or select
off
to disable fail-safe operation. Failsafe mode should not be
used on batch relays assigned to total.
Programming Time Delay
The
On
and
Off
time delays may be programmed for each relay between 0 and 999.9 seconds. The
relays will transfer only after the condition has been maintained for the corresponding time delay.
The
On
time delay is associated with the set point.
The
Off
time delay is associated with the reset point.
Relay Action for Loss of 4-20 mA Input (Loop Break)
The loop break feature is associated with the 4-20 mA input. Rate alarm relays may be programmed to go
to one of the following conditions when the controller detects the loss of the input signal (i.e. < 0.005 mA):
1. Turn
On
(Go to alarm condition)
2. Turn
Off
(Go to non-alarm condition)
3. Ignore (Process as a low signal condition)
Note: This is not a true loop break condition; if the signal drops below 0.005 mA, it is interpreted as a
“loop break” condition.