Previous user, new account, locked out of my old one.
I am looking for a way to limit the Historian Data Logging to keep from logging values above a certain threshold.
For example. My tags value can be as must as 16,959. However the 'real' data during operations will never go above 6000. So I would like to only record datapoints below 6000.
Anyone know of a way to do this?
You could use tag scaling to clamp the actual value of the tag to a certain range, but if the value of the tag is 16,959, that's what the historian is going to record. There's no way to 'intercept' inserts from the historian. You might be able to post-process in your DB on a trigger or something, but as the saying goes... garbage in, garbage out.
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I was trying to do it with a memory tag or a reference tag. Now I am using an expression with a simple if statement. Seems to be helping. I am getting some unexpected negative values in the plot now.