I just upgraded our Ignition system to version 7.5.3 from 7.3.5, and now I am getting bad tag quality for all tags from our sites with PCS7 systems. OPC server is connected, and I am getting readings, but the tag diagnostics say bad quality.
What is going on? I have disabled and enabled the OPC servers for the sites, and the tag quality is still bad.
The timestamp stuff has been relaxed in 7.5.4 to allow up to a 10 seconds delta in timestamps. This is likely the cause of your bad quality tags.
The latest beta version of the UA module (here) should include this change.
If your timestamps are greater than 10 seconds in the future you’ll have to do some work to get your servers and timestamps synced up a little better. Whether or not the server is in another timezone is not a problem since we’re dealing with the delta on UTC times.
These changes regarding values coming from “the future” were sort of forced on me by the OPC-UA compliance testing and I’m doing what I can to relax them a bit while still remaining compliant.
When a driver reads a value from a PLC and hands it off to the server it sets the source timestamp for that UA DataValue to that system’s current time. This timestamp is embedded in the value that is transferred to any UA clients consuming those values. The UA client then checks that timestamp embedded in the value against the current timestamp of that machine to make sure that it’s not from the future more than 10 seconds.
For this to happen (as of 7.5.4-beta4) the time delta between client and server machines has to be greater than 10 seconds. If you’ve got your machines keeping their timed synced via NTP (or whatever else) you shouldn’t really ever see a drift of more than a 1-2 seconds.
What do the messages in the logs say now? They should include the amount of time delta in the messages.
Is there a way to disable the timestamp check? Our control systems are directly connected to the internet, so the windows time synchronization is not working properly. I was able to manually change the times, but they are already showing a difference again after 5 days.
There isn’t currently a way to disable it, but I’ll see if that’s something I can do.
In the meantime, make sure the Windows Time Service is running on your servers and if necessary change the interval at which the services synchronize their time.