When I reboot my system it seems like the SQL bridge starts logging before the OPC server has had a chance to collect the first pass of data. This creates a zero value in the table that we query for the state report. Is it possible to delay for a few seconds or control the logging of data so that this doesn’t happen?
If it’s from triggered transactions, then you may want to look at this…
This comes up from time to time. You also see it simply when you stop the group and restart it, which causes a new subscription. The “prevent trigger caused by group start” might help, but probably only in very specific conditions (on 0).
Ultimately, I don’t know that there’s a sure-fire way to prevent this right now. We’ve had various ideas in the past for minor feature tweaks, such waiting for the first subscription update to come in before enabling logging, but haven’t ever implemented one. There are some other options, depending on what you’re willing to do with the data that’s logged: you could turn on the “async” trigger mode that only logs when data changes, you could create an item that referencing the quality of one of the points and use that as a trigger, as the values shouldn’t be “good”/(192) when they’re starting up, or you could set it to log the quality, and simply run a query that deletes bad data from the database once in a while.
I’m pretty sure we’ll try to handle this case better the next time we working on updating the SQL Bridge module.