We upgraded to 8.3.1 about a week ago and we noticed that some of our history was not being shown in our easy chart. Many tags are being saved to the same database so the database isn’t full because I still have active history records from tags not on a micro800.
I haven’t changed anything regarding these tags since I created them.
In the picture below I'd assume all of those data points to be part of the history but they are only the value at that point in time.
And to be clear all of this worked prior to upgrade to 8.3.1, 8.3 was fine.
Since I mentioned the easy chart here is what that looks like (interpolation is turned on)
I talked to a couple of devs on the tags and historian team, and we think this issue is likely solved in the 8.3.2 RC with IGN-14714.
When we added the option to configure the timestamp source on the OPC UA Connection, we introduced a bug when using the option to prefer the source timestamp. If the source timestamp was not valid, we didn't properly revert to using the server timestamp.
You can see a reasonable timestamp in your query, because it is added sometime after the Ignition tag value is changed, but I guess sometime before the historian processes it for history. I'm still fuzzy on the details for that part.
You could try a different timestamp preference on your OPC UA connection config, but that would change the timestamp source for all of the tags using that connection. If you can use the 8.3.2 RC, give that a try. That's probably not recommended for production (since it's pre-release), so your only other option may be to downgrade back to 8.3.0.
@Cody_Morgan, I'm curious what would be the side effects of changing the timestamp source? It seems to have solved the issue on my development server but I'm not sure if there are effects I'm not aware of for the other histories.
It depends on the source of your OPC tags. When using OPC_PREFER_SOURCE, we will use the timestamp from the source of the value, if available. If it's not available, we will fallback to using the timestamp of when the value was received in the OPC UA server. When using OPC_PREFER_SERVER, we will ignore the value of the source timestamp, using the timestamp from the OPC UA Server.
Since this is a connection-wide setting, you have to be careful. Some of the tags within your connection may have meaningful timestamps from the source that you wouldn't want to ignore. If your OPC UA connection is to the Ignition OPC UA server, and the only thing feeding your OPC tags are a few PLC drivers, and the PLCs do not provide their own timestamps, then you shouldn't notice a difference.
If you need help determining which tags may have source timestamps, let me know which drivers (or other data source) you're using, and I can help you figure it out.
