Advice on hanging Resident script (suspect storage get/set)

[admin]

You don't need storage in a resident script like this. All variables will keep their values after each call, but will be nil on first script run, so you have to check for that. Sending a telegram once a minute is not a problem. You should use grp.update instead of grp.write if you don't need this value on KNX/TP bus.