I am trying to measure the uptime and downtime of our process.
I have setup a transaction group where an expression tag named uptime uses the time meter to determine the uptime of our process.
How can I get the time meter value to reset to zero at midnight?
The most common case for logging hour or event meters to the database is to have new records default to all 0 values. Then just adding a new record will zero your values.
You can also reset hour and event meters now from a tag. So if you create an expression SQLTag that is equal to 1 and midnight, it can be used to reset the hour or event meters.
So once I set up the tag that is equal to one at midnight, should I do a write target to the uptime tag?
No, he’s referring to this option on the tag config. This was introduced in 7.5 (I think? Maybe 7.4, can’t remember).