Watlow Series 97 - Manual (Page 38)

Alarm Silencing
Alarm silencing has two uses:
1. It is often used to allow a system to warm up after it has been started up. With alarm
silencing on, an alarm is not triggered when the process temperature is initially lower
than the alarm low set point. The process temperature has to enter the normal operat-
ing range beyond the hysteresis zone in order to activate the alarm function.
2. Alarm silencing also allows the operator to disable the alarm output while the controller
is in an alarm state. The process temperature has to enter the normal operating range
beyond the hysteresis zone in order to activate the alarm output function.
Alarm Silencing 2 [SiL2] (Output 2 Menu) allows you to view or change whether alarm
silencing is on. If Alarm Annunciation 2 [Anu2] (Output 2 Menu) is set to [`YES], the out-
put 2 indicator light will remain on and an alarm message will appear in the display, even
though the alarm is silenced.
Figure 5.10 — Alarm silencing.
Normal Operating Range
Alarm
enabled
here
Alarm
triggered
here
Startup,
Alarm
disabled
Time
Temperature
Alarm High
Set Point
Alarm Low
Set Point
Process
Temperature
Hysteresis
Hysteresis
5 . 1 0 ■ F e a t u r e s Wa t l o w S e r i e s 9 7