Watlow MICRODIN - Manual (Page 43)

Wa t l o w M i c r o D I N 4 . 1 1
Features
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.
Figure 4.11 — Alarm Settings
Alarm Set Points
The alarm high set point defines the temperature or process value 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 or process value 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.
Alarm set points or deviation can be viewed or changed with Alarm High and
Alarm Low (Alarm Output Group).
Alarm Hysteresis
Alarm hysteresis is a zone defined by adding an hysteresis value to the alarm
low set point or subtracting the hysteresis value from the alarm high set point.
Once an alarm has occurred it will not clear until the process value is above the
alarm-low setting or below the alarm-high settings by a margin equal to the
hysteresis. Example: An alarm starts when the process value reaches the alarm
high setting. The alarm will not clear until it is below the high setting by an
amount equal to or greater than the alarm hysteresis.
The alarm hysteresis value can be viewed or changed with Alarm Hysteresis
(Alarm Output Group).
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