Parameters > Citect.ini File Parameters > Alarm Parameters > [Alarm]ScanTime


Determines the rate at which alarms are scanned and processed. A value of 500 (the default value) indicates that CitectSCADA tries to process the alarms every 500ms. However, if CitectSCADA cannot read all the alarm data from the I/O device within 500ms, the alarms are processed at a slower rate. For example, if it takes 800ms to read all the alarm data from the I/O device, CitectSCADA processes the alarms every 800ms.

If you increase the alarm scan time, the Alarms Server uses less CPU (because it does not need to process the alarm records as often). The amount of data read from the I/O device is also reduced, so that other processes (Trends, Reports, and the current page) get their I/O device data more quickly.

Note: This parameter is modified by the Computer Setup Wizard as well as the Computer Setup Editor.

Allowable Values: 0 to 60000 (milliseconds)

Default Value: 500

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