INFO
The total delay before the alarm Action is activated is the Operate time for the alarm plus the Delay parameter.
4.2.6 Inhibit(s)
Inhibits stop the alarm Action when the inhibit conditions are active. When an inhibit is active, the controller does not activate the
alarm Action, even if all the other alarm conditions are met. Inhibits are automatic and are not controlled by the operator.
If an inhibit with active conditions is created for an active, unacknowledged alarm (with or without a latch), then the alarm state
changes to an inactive, unacknowledged alarm (with or without a latch). The alarm needs to be acknowledged (and unlatched if
required) before the alarm is removed from the alarm list.
INFO
Inhibited alarms are not shown in the alarm list, unless they have occurred and are unacknowledged before they were
inhibited.
The controller types are delivered with the appropriate default inhibits for each alarm. You can remove these inhibits, and/or add
more inhibits. In addition to the default inhibits, you can also configure three customisable I/O inhibits for selection.
More information
See Alarms, Customised inhibits for more information.
For example, for a GENSET controller, for generator under-voltage, the inhibits Engine not running is selected. This means that if
the genset is either starting up, or if there is no running detection, the generator under-voltage alarm is disabled.
In addition to the default inhibits available, some alarms include permanent inhibit conditions. These inhibits are not configurable,
and are described under the alarm that uses them.
INFO
For some alarms, inhibits are not applicable. The controller will not allow you to select any inhibits for these alarms.
4.2.7 Enable
Some alarms can be Not enabled or Enabled, according to your requirements.
If the alarm is Not enabled, it does not respond to changes in the operating values, and is never activated.
If the alarm is Enabled, it is activated when the alarm Set point and Delay are exceeded. However, if the conditions for one or more
inhibits are met, then the alarm and its Action are inhibited, and not activated.
CAUTION
Do not change an active alarm to Not enabled.
INFO
If you change an active alarm to Not enabled the alarm action continues. The alarm action cannot be reset until after the
alarm is enabled again.
4.2.8 Trigger level
If the reference value must be equal to or higher than the Set point to activate the alarm, a High Trigger level is selected in the alarm
configuration.
Similarly, if the reference value must be equal to or lower than the Set point to activate the alarm, a Low Trigger level is selected in
the alarm configuration.
DESIGNER'S HANDBOOK 4189340911K UK Page 100 of 521
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