I am having an issue that I am not sure how to solve. I am fairly new to opto so it may just be a lack of experience. We have several flow meters that are analog inputs but either due to instrument drift or non steady current will sometimes read a negative value, especially when the meter is idle. We use these values for totalizers which then add these negative values which makes the total go down so we overshoot the target load.
For some cases I think this can be fixed by setting a variable equal to the total value at the end point so it won’t keep totaling the idle values or the other thought I had was essentially to disable communication to the analog point when not trying to load through the meter so the total doesn’t change.
The main problem I am not sure how to solve is certain totalizers work with PID loops and sometimes those loops need to stop and start flow in the middle of loading a batch. Is there a built in function to where the totalizer can just ignore values less than zero or would I need to figure out a way to program a self check and throw out negative values. Please let me know thanks.