That might work and it is an approach I never considered. I’ve never used the Exec transform before.
What didn’t work for you? Have you installed the exec transform? It might require the exec1 binding to work. Check the logs for errors.
I think most of us create a rule to update a DateTime when the associated Item gets an update but I’m intrigued by the idea of doing the same in a transform. Of course for it to work date needs to output in the correct format that can be parsed by the DateTimeItem.
I don’t know the nature of your messages but you might want to use received update as the trigger so the rule runs even when an mqtt message comes in that doesn’t result in a state change.
See:
Not quite. You can trigger a rule based on updates to a group but the rule will trigger multiple times per Item update. Or you can trigger a rule with each item listed as a separate trigger and use the trick in the working with groups link above to identify which Item triggered the rule.
