Built-In integer value that is generated automatically by the system to implement various timer models:
•SquareWave:
the value toggles between 0 and 1.
•Pulse: the the tag changes to 0, then changes immediately to 1.
•DelayOff: the tag behaves as a PLC Timer Off . During the runtime, if you set the tag with some value other than the StartValue, the tag will hold that value for the period specified in the Interval. The tag goes back to its StartValue after the period of time (Interval)
•Comparer: the tag is set to 1 after the specified comparer Interval, and then goes back to zero at midnight .
For the SquareWave, Pulse and Comparer, If you set the tag StartValue, the tag toggles between 0 and StartValue (instead of 0 and 1) .