[SOLVED] OH 3.1.0.M3 - Modbus stops polling / updating item states

After upgrading to OH 3.1.0.M3, I just realised that the Modbus binding stops polling / updating item states for some items. No changes to setup besides updating OH. Strange though, as some items update as before, whereas some don’t, without any logged issues. Also strange, as the issue appears for Data things within the same Poller, i.e. one Data thing working as before, one Data thing stops updating.

For reference: Using Modbus TCP.

That suggest it’s not stopped polling at all, then.
You could if you wish verify that by linking a DateTime Item to a lastReadSuccess channel and observing.
Anything specific to your suspects, like using a transformation?

Sure it’s not a display issue, like -

@rossko57:
I do not see these issues related, as the item having display issue keep getting state changes, whereas the modbus items just stopped getting updates immediately at the time OH was upgraded (see below). As for the item shown below, there are no transformations being used, just Metadata/State Description: Pattern %.0f RPM, so I do not have any clues to what could be the issue.

I’ve no idea what that is, or what it is supposed to look like. Remember, we just don’t know exactly what you mean by “updates stopped” because we don’t know what and where you are looking at to decide that has happened.

If you think the binding is messing up, then follow the troubleshooting instructions in the documentation to get debug logging

@rossko57
Just highlighting the item state graph, to illustrate the immediate stop in response, coinciding with the timing for OH upgrade.

Raised as an issue here to check if others have been experiencing the same.

Will for sure chase it up with further debug logging.

Okay, with just the graph to work with, maybe you have a persistence problem.

Having done some additional debugging, the modbus part is working as it should, meaning polling is performed with success, as well as channels being updated with state changes. So there seem to be some issue related to channel/item link, as some channel/item links works as before, whereas some channel/item links just suddenly broke (apparently as part of updating OH to 3.1.0.M3).

EDIT
In fact, there seems to be an easy (although annoying) fix to the problem: From main UI, unlinking channel/item and linking them back again restarted the state updates.

@rossko57
Although, the gain/offset profile does not seem to be included in the 3.1.0.M3 version of the modbus binding.

That’s unusual, implies something changed about the Thing.

You’ve not said what you updated from.

Tell us more; were you using that before? Might be the change that broke your links.

As an aside, I’d like to see that profile moved to general system anyway, not just modbus.

And there we probably have the reason: I was updating from OH 3.0.1 stable to 3.1.0.M3, previously using a manual install of Modbus binding. Assuming the PR had been merged, I re-installed the Modbus binding from main UI under 3.1.0.M3.

However, the PR has apparently not been merged, and as the manual install version of the binding does not work under 3.1.0.M3 (error related to import-package org.apache.commons), I end up using the 3.1.0.M3 Modbus version, without the gain/offset profile. Unlinking and re-linking channels/items solves the issue, although the issue occurred also for regular Number channels, without transformation/gain profile.

I was just using a 0.1 °C gain for temperature readings, so now I’m back to using JS transformation and metadata for state description.