I am trying to set up historical recording for a tag.
I have selected the historical scan class to the following:
the table in the SQL database remains empty even when I trigger the tag multiple times and have tried several setups.
I’ve tried “Any Change” and = 1 and I’ve varied my testing.
What could I be doing wrong?
What is the realtime scan class for that tag? By the way, your driven scan class has the same rate for slow rate and fast rate. Essentially, it is always going to log every 50 ms no matter what the trigger value is. You should probably set the OPC Data Mode to Subscribe and not read.
my realtime scan class is “fast” and it is set to 50 ms, direct, and subscribed.
All I am trying to do is record values of these tags every time another tag becomes true.
So naturally I thought that I should use ONE-SHOT and set the trigger tag to = 1.0
and I only want to record the data once when the trigger is activated.
Afterwards I have code that will reset it.
It seems like through my testing of this feature, it has spoty results, only logging information if the tag values have changed instead of only looking at whether the trigger had changed.
I think the problem is that we only log the values when they change and do compression in analog mode. I think you want to use a transaction group and not SQLTags historian. A transaction group can log data to any table you want and it is built-in to use triggers and only do it once when it is active.