A configured alarm can be in one of the following states.

• Disabled
• Off Acknowledged
• Off Unacknowledged
• On Acknowledged
• On Unacknowledged

The illustration bellow is the state diagram for configured alarms.

When Citect starts up, all alarms default to the OffAck state. When an alarm becomes activated it moves to the OnUnack state. Refer to the diagram above.

Analog Alarms have sub-states when in an on state. Digital Alarms have no sub-states.

Note: An alarm can bypass the High state and display the High High state immediately if the tag surges to the High High region and Citect does not read the tags value while in the High State. The same applies for the Low states.

Displaying Alarms

The AlarmDsp() function is used to display alarms. (eg. used on the Alarm Page, Summary Page, Hardware Alarms etc.)

The Alarm Page: {AlarmDsp(An,Count,0)};

• Displays all alarms in state 1, 2 & 3(ie. On Unack, Off Unack, On Ack)
• Alarms are displayed in order of state:

1st - On Unack
2nd - Off Unack
3rd - On Ack

• If there is more than one alarm in a state, the alarms in that state will be displayed in order of the OnTime. (most recent on top)
• State change (or sub-state change) of an alarm is represented on existing entry by change in font and updated information. (OffTime, High to High High etc.)
• There is only ever one entry per alarm on this page.

The Summary Page: {AlarmDsp(An,Count,10)}

• Each time an alarm changes state from off -> on or changes sub-state (ie. High -> High High etc.) a new entry for the alarm is displayed at the top of the list.
• Any other state change is represented on existing entry by change in font and updated information. (OffTime etc.)
• Displays all Summary Alarms (ie. On Unack, Off Unack, On Ack, Off Ack)
• Alarms are displayed in the order of the time that each was activated. (most recent on top)
• May display more then one entry per alarm on this page.
• An entry will remain on the alarm summary for a minimum of {[ALARMS]SummaryTimeout} minutes or while it is still On before it is removed. (see summary device below).

Last Alarm @ An11: {AlarmDspLast(11,1,0)}

Essentially displays the first alarm of the alarm page at An11.

Log Device

Each time an alarm changes state or sub-state it gets logged to the Log Device.

Summary Device

Each alarm entry on the alarm summary page gets logged to the "Summary Device".  The conditions in which the logging occurs is:

if SummaryLength is exceeded then
   Log to summary device
If SummaryMode is set to "Log in On time" then
   If SummaryTimeOut minutes has elapsed since OnTime then
      If Alarm is Off then
         Log to summary device
      If Alarm is On then
         Log to summary device as soon as Alarm goes off
If SummaryMode is set to "Log in Off time" then
   If SummaryTimeOut minutes has elapsed since OffTime then
      Log to summary device