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