Hi, i have a opc tag that we use for interacting with a plc. The tag is there to stop the machine from operating until the tag is set to false. I have a script that users use to set the tag to true or false depending on some circumstances.
Now i noticed the tag sometimes changes to false with no apparent reason. User does not run the script so i am wondering what did it.
Is there a way to check what caused the tag to change?
Thanks!
Turn on and configure the audit subsystem.
Hi Phil, thanks! I managed to track down tag writes i was looking for in the audit table. I cant actually tell what is doing that tag write.
Actor and Actor host are unknown, originating system is "project: MyProject".
We write to the tag from gateway events and few buttons in application. I can see that there are events that do have the actor and actor host, those are the ones that user does.
Right, gateway events are considered privileged, and aren't associated with a user.
Auditing is not really suited to troubleshooting your gateway events. You'll have to study your code paths yourself.