We have a flow meter tag, that is ranged 0 to 10 sm³/s. Currently, the PI data stored has a resolution of on ±0.1 sm³/s (i.e. it tells me that the current flow is 1.6 sm³/s, and I won't get an update until it hits 1.5 sm³/s). I wanted to increase the resolution on it.
So: I modified the tag attributes. CompDevPercent was set to 0.01, but the span was set to 100 ("zero" is 0 by the way). So I changed the span to 10. This changed the compdev to 0.001. Excdev is at 0.005.
However, this hasn't improved things. I still don't get any better data resolution than ±0.1 sm³/s.
Any suggestions? I was wondering whether the DCS (a Bailey) is filtering the data before it gets to the PI Buffer server.