FSQL ASYNC Update question

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1

I was wondering, I think I fixed the problem using this checkmark setting but I wanted to run it up you ideas and see if indeed this is the best approach.

Before I checked this setting for one of my groups. I had the setting set at 1 seconds scan time, and bi-direction DB wins. If I went to the PLC and manually entered the data for one of the fields in this group, sometimes it would take, and sometime it would still send the data which was in the Database back out to the PLC and so my new settings would not take ahold.

Once I checked this box now it seems to take the information on the first try at the PLC level and if it changes at both the DB and the PLC the DB wins.

So did I make the right choice?

Thanks and have a great day.

2

The asynch checkbox makes the group only evaluate when a change has occurred to an OPC value since the last update. This is useful when you only want to log changes, and not just on a set interval. This setting takes precedence over the rest of the trigger settings. So, you are guaranteed to see all value changes.

With that box unchecked, the group looks for value changes at the update rate specified. With that you may miss value changes and if the group is set to DB wins than the old db value will get written down to the PLC.

In your case, you can either check it like you have or make the update rate faster. So, what you did is correct.