Watlow MICRODIN - Manual (Page 44)

4 . 1 2 Wa t l o w M i c r o D I N
Features
Process or Deviation Alarms
A process alarm uses one or two fixed set points to define an alarm condition.
A deviation alarm uses one or two set points that are defined relative to the
control set point. High and low alarm set points are calculated by adding and/or
subtracting offset values from the control set point. If the set point changes, the
alarm set points automatically change with it.
Alarm Type (Alarm Output Group) allows you to view or change whether the
alarm will function as a process or deviation alarm.
The alarm deviation value can be viewed or changed with Alarm High and
Alarm Low (Alarm Output Group).
Alarm Latching
A latched alarm will remain active after the alarm condition has passed. It can
only be deactivated by the user. An alarm that is not latched will deactivate
automatically when the alarm condition has passed.
Alarm Latching Mode (Alarm Output Group) allows you to view or change
whether an alarm will latch.
Figure 4.12 — Alarm Latching
Normal Operating Range
Alarm High
Set Point
Time
Temperature
Alarm Low
Set Point
The alarm state continues until the
temperature drops to the alarm high
set point minus the hysteresis. A
latching alarm could be turned off by
the operator at this point. A non-
latching alarm would turn off
automatically.
The alarm state begins when the temperature
reaches the alarm high set point.
Process
Temperature