Value Changed Event Script- Update Speed

Hello. I’m working in version 7.7.4.
I set up a pair of memory tags, with boolean data type. I then set up a script on one to transfer the value to the other on value change. See below:

These tags are using the default scan class. When I change the value of the original tag, it takes minutes (around 5) before the script runs and writes the value to the second tag. Any ideas as to why there is a delay? Shouldn’t it run at the scan, given that the value would have changed?

Thanks for the help!


I’m not able to replicate your issue, though I am running a more recent version of the gateway.

Have you checked your gateway status/logs for signs of anything unusual? Also check your scan class definitions to be sure it’s running at the default rate of 1,000 ms.

Slightly related: when checking the quality of a tag, you can simply use: currentValue.quality.isGood() which returns either True or False. Not sure if that’s available in 7.7.4, though I’d assume so.

When trying it again this morning, now it functions properly. I didn’t change anything in the gateway or project between then and now. As they are memory tags, I don’t think it was caused by a networking issue. Is it possible that the gateway was getting slowed up / backed up?

Memory tags that aren’t client tags are still stored in the gateway, not your local machine.

If you can access the gateway: go to status->performance on the left to see historical trends of resource utilization as well as any slow events.
Under status->logs you can see anything that may have went wrong at the time (in the gateway).

Unfortunately, in 7.7.4, I don’t have access to those windows. Is there another way to look at this info?

I’ve never used 7.7, and can’t seem to find the relevant documentation. Maybe someone a little less green can help :blush:

The trends are only available in 7.9.x. The logs are available in older versions, but in the Configure section under System => Console.

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