AlarmEventQue
- Last UpdatedMay 14, 2025
- 2 minute read
Opens the alarm event queue. The alarms server writes events into this queue as they are processed. The events include activated, reset, acknowledged, enabled and disabled alarms.
Note: This function can only be called on the alarm server.
To read events from this queue, use the QueRead or QuePeek functions. The data put into the queue is the alarm record identifier (into the Type field) and the alarm event format (into the Str field). The function puts every state change into the queue. Plant SCADA does not use this queue for anything.
To use this function, you need to enable the alarm event queue with the [Alarm]EventQue parameter. This parameter will tell the alarms server to start placing events into the queue. The [Alarm]EventFmt parameter defines the format of the data placed into the string field. You can enable the EventQue parameter without setting the event format so that the alarms server does not place a formatted string into the queue.
Enabling this formatting feature can increase CPU loading and reduce performance of the alarms server as every alarm is formatted and placed in the queue. You should reconsider using this feature if a decrease in performance is noticeable.
The event queue accesses alarm server data using the user profile specified on the Configure Server User page of the Computer Setup Wizard (see Configure the Server User Page). Access to the alarm data will be restricted by the areas and privileges defined for this user.
Note:
• If you call Cicode that logs in a different user on the alarm server process, it
will log out the profile used by the event queue. This will restrict the event queue's
access to the alarm server data.
• If the alarm event queue is enabled and you need to run the alarm server process
with a specific user at startup, it is recommended that you specify the required user
via the Computer Setup Wizards's Configure Server User page rather than logging in
a user via startup Cicode.
The maximum length of each queue is controlled by the [Code]Queue parameter. You may need to adjust this parameter to avoid missing alarm events. When the queue is full, the alarms server will discard events.
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UNINTENDED EQUIPMENT OPERATION You may need to adjust the [Code]Queue parameter so as not to miss alarm events. When the queue is full, the Alarms Server will discard events. Failure to follow these instructions can result in death, serious injury, or equipment damage. |
Syntax
AlarmEventQue()
Return Value
The handle of the alarm event queue, or -1 if the queue cannot be opened.
Related Functions
QueRead, QuePeek, TagWriteEventQue
Example
hQue = AlarmEventQue()
WHILE TRUE DO
QueRead(hQue, nRecord, sAlarmFmt, 1);
/* do whatever with the alarm event */
...
Sleep(0);
END