I am currently developing an application that tracks errors currently by updating an error tag every time the value for the tracked parameter violates the limit within tag event scripting. I would like to do be able make it so that only the most recent four hours of errors are counted. What would be the best way to do this? Should I use a SQL Table, Transaction Groups, or is there a way I could do this within tags (Preferable Option if Possible). Thank You!
To clarify, when you say "error" are you referring to an errored state of the tag, such as a "bad" quality. Or, a tag value that is outside predetermined bounds. From your initial description, it seems as if you are referring to a tag value, which can be handled by creating an alarm that is triggered from a high and low and low set points. If this is the case I would recommend having a look at configuring the alarm properties for the tag, there is a user documents page here.
If alarming is not what you had in mind, I would suggest creating a Transaction Group which you can either prune records older than 4 hours of configure your query to only select records within that timeframe. The user document page for the Transaction group and its configuration can be found here.
If neither of those two answers are tracking with what you are looking for, would you elaborate on how you are expecting these errors to be counted and displayed?