Currently, the way to have a trigger on a unsupported item is with a nodata() function on that item.

If we use a "discard with heartbeat" on that item, the nodata() can fire if the time set in lower than the heartbeat.

If an item is working fine but the values are the same, the new data won't be saved into the DB. It's kinda the same as the item becoming unsupported, as it won't have any new data in the DB.

In the case of a discard, it's expected, in the case of a unsupported item, it's not.

Can you please add a trigger function to check for unsupported item that does not fire when there is no data because of the "discard with heartbeat" preprocessing function ?