1 Reply Latest reply on Nov 14, 2014 4:52 PM by Gregor

    Can you generate an event frame with a single time stamp of when an event started?

    rbendio

      I have a breaker that I would like to generate an event frame time stamp of when this breaker trips.  I don't care how long the event lasts, I just need to know when the event occurred.

       

      So if a breaker trips or closes three times during a month period, I would like to generate a time stamp of each change of state.

       

      I've tryed several functions like

       

      PrevVal('BREAKER','*')<>TagVal('BREAKER','*')

       

      but when I back fill the event it seems to skip events.

       

      Ric

        • Re: Can you generate an event frame with a single time stamp of when an event started?

          Hello Ric,

           

          Using relative times can be tricky depending on when things become evaluated. Are you trying to get the TimeStamp or the value? To get the TimeStamp, please use e.g. PrevEvent() At what frequency is the tag serviced? As said, before relative times can be tricky because you never know exactly when the evaluation happens. PrevVal('BREAKER','*') can refer the current snapshot or the previous (archive) event. You can use a little trick to move the equation to the safe side e.g. PrevVal('BREAKER','*+1s') should always return the snapshot value if the sample frequency is > 1s.