Applies To:
  • CitectSCADA x.x

Summary:
I don't seem to understand how the Alarm Summary works or how I can alter it so that it works how I want it to. Also sometimes my Alarm Summary history files do not get created. 

Solution:
The Alarm Summary shows one line for each alarm as opposed to the Alarm Log which logs one line for each change of state of an alarm. The time stamp and state fields are updated on this line as the alarm changes state. Following is a typical format for an alarm summary entry.

{TAG,8} {NAME,30} {SUMDESC,30} {ONTIME,8} {OFFTIME,8} {DELTATIME,8} {ACKTIME,8}

The alarm Summary is held in the Computers RAM and can be viewed using the PageSummary() function. When an alarm is activated an entry for that alarm will appear in the Summary and the OnTime (and OnDate) field will be set to the current time. When an alarm is complete ie. it has been deactivated then it will be logged to the Summary Device after a predetermined period of time. Note: it does not have to be acknowledged, if it has not been acknowledged by the timeout period then it will still be sent to the Summary Device and the acknowledge time will not be saved. By default the alarm will be held in the Summary (RAM) for 60 minutes after it has been deactivated, then it will be removed from RAM and stored in the Summary Device. After this point in time the alarm cannot be viewed by the standard PageSummary() function. To view the alarms stored in the Summary device you would need to have some Cicode to read the device and display it on the screen. By default the alarms will be sent to the Summary Device in OnTime order, therefore if alarm A is activated at 0 seconds, alarm B is activated at 10 seconds them alarm B is deactivated at 20 seconds. Alarm B cannot be sent to the Summary device before alarm A so if alarm A stays active for a long time then both alarms (and any other alarms that activate after these ones) will be held in RAM until alarm A is complete or until the max summary size is reached. This default operation may not suite your application, the operation can be controlled with the following parameters.

[Alarm]SummaryMode=
0 = Log in ON time order and remove from the list (Default)
1 = Log in ON time order but leave in list
2 = Log in OFF time order and remove from list
3 = Log in OFF time order but leave in list
[Alarm]SummaryTimeout=
Default is 60 minuets
[Alarm]SummaryLength=
Default is 1000 alarm entries

A typical requirement is to be able to save the entry to the Summary Device immediately on completion (on deactivation) and to able keep the entry in RAM so that it can still be viewed on the Summary page. The following recommended example will give that functionality.

[Alarm]SummaryMode=3 ;Log in OFF time order but leave in list.

"Leave in list" will allow the alarms to stay in RAM after it is logged to the Summary Device, the alarm will stay in the list until the list reaches the [Alarm]SummaryLength=1000 value, then the oldest alarm will get dropped from RAM. The "OFF time order" will ensure that no alarms are prevented from being logged due to earlier incomplete alarms. This setting also can fix the problem where the history files do not get created. If you do not particularly like this order then you can try logging to a database and then resorting.

[Alarm]SummaryTimeout=0 ;Log immediately on completion

This means as soon as the alarm has deactivated then is can go to the Summary Device. It is recommended to use a zero value for this only when using [Alarm]SummaryMode=1 or 3

 

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