Watlow Series 97 - Manual (Page 37)

Process
A process alarm uses one or two absolute set points to define an alarm condition.
The alarm process value of output 2 can be viewed or changed with Alarm 2 High [A2hi]
and Alarm 2 Low [A2Lo] (Alarm Menu).
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 2 Latching [LAt2] (Output 2 Menu) allows you to view or change whether the out-
put 2 alarm will latch.
Clear a latched alarm by pressing the Reset key after the alarm condition has passed.
Figure 5.9 — 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
Alarm Hysteresis
Wa t l o w S e r i e s 9 7 F e a t u r e s ■ 5 . 9