Watlow 97 series, Руководство пользователя

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Alarms
An alarm takes some action, usually notifying an operator, when the process temperature
leaves a defined range. A user can configure how and when an alarm is triggered and
whether it turns off automatically when the alarm condition is over.
Alarm Set Points
The alarm high set point defines the temperature that will trigger a high side alarm. The
alarm high set point must be higher than the alarm low set point and lower than the high
limit of the sensor range.
The alarm low set point defines the temperature that will trigger a low side alarm. The
alarm low set point must be lower than the alarm high set point and higher than the low
limit of the sensor range.
Process alarm set points for output 2 can be viewed or changed with Alarm 2 High [A2hi]
and Alarm 2 Low [A2Lo] (Alarm Menu).
Alarm Hysteresis
Alarm hysteresis is a zone inside each alarm set point. This zone is defined by adding the
hysteresis value to the alarm low set point or subtracting the hysteresis value from the
alarm high set point.
An alarm state is triggered when the process value reaches the alarm high or alarm low set
point. Alarm hysteresis defines how far the process must return into the normal operating
range before the alarm can be cleared.
The alarm hysteresis value for output 2 can be viewed or changed with Hysteresis 2 [hYS2]
(Output 2 Menu).
Figure 5.8 — Alarm settings.
Normal Operating Range
Low Side Alarm Range
High Side Alarm Range
Alarm High Set Point
Alarm Low Set Point
Time
Temperature
Alarm Hysteresis
Alarm Hysteresis
5 . 8
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F e a t u r e s Wa t l o w S e r i e s 9 7