3 Replies Latest reply on Nov 5, 2015 1:02 AM by stang

    Can a multi-state object use a tag with a negative value?

    blancharap

      I have a multistate object I am trying to create using a tag, but the value of the tag is negative and it won't give me an option for a negative values.  I read that the values are automatically chosen based on the range of the tag.  Are there any settings that can be changed to allow negative values for the multi-state object?

        • Re: Can a multi-state object use a tag with a negative value?
          stang

          Hello Aisha,

           

          As you have stated, the lower limit is automatically defined as the tag zero and the upper limit is automatically defined as the tag (zero + range).

           

          Negative values are supported if the zero is negative. If you need to go beyond the limits for whatever reason, but cannot or do not want to change the zero/range, you can create a PI Calc data set with the expression set simply to the value of the tag in question. In that case, there will be no restrictions imposed on the range of values allowed by the multi-state symbol.

           

           

          Note that the refresh interval will be used instead of the normal update rate of the tag.

            • Re: Can a multi-state object use a tag with a negative value?
              blancharap

              Thanks for your response.  I won't be able to use the calculation however because it doesn't update fast enough (every minute, I would like to see every second) to see what I want to see.  If I change the 0 from 0 to a negative number does that change what zero is for the tag?  Example:  zero=0 tag value =0  If I change the if zero=-50 will the tag value=50?

                • Re: Can a multi-state object use a tag with a negative value?
                  stang

                  Hi Aisha,

                   

                  If 1 minute is too long, then you will indeed have to change the tag zero (which is probably a better option anyway). The zero does not affect the tag values at all - it is simply an indication of what the expected lowest value is for the tag. It will affect things such as the labeled value range of gauges in Coresight, or as you have just experienced the accepted value range for multi-state symbols.