Gain-Offset Correction only working in one direction

Setup, Configuration and Use Items & Sitemaps
1

I have a HVAC unit connected to openhab using modbus. I use the Gain-Offset Correction profile to link the channel to the item.

Here is the item:

billede
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And the profile:

billede
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The reading of the value works and I get something like “20 °C”. When I change value on the device, the item in openhab gets updated.

But, when I use the stepper on the item configuration page to change the value I get the following warning:

22:08:42.445,"WARN","org.openhab.binding.modbus.internal.profiles.ModbusGainOffsetProfile","Cannot apply gain ('0.1 °C') and pre-gain-offset ('100') to state ('21') (formula '21'/'0.1 °C' - '100') because types do not match (towardsItem=false): Cannot process command '21', unit should compatible with gain"

How do I get the stepper to return the value including the unit?

2

How did you define the stepper? MainUI or Sitemaps?

3

On the Item page in MainUI. It is just the standard widget for the item.

billede
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4

What do you see in events.log when you change the value using that widget?

The first thing I would try is add a “default stand-alone widget” and set the min, max, step and offset to a value with units. See if that makes a difference.

Also check your state description pattern. It shouldn’t matter but before OH 4 it did have influence.

The gain-offset profile has often been troublesome. In a pinch, a script transform could be used which we can make work with the UoM.

5

It is not allowed to enter units in the min, max, step and offset fields in the “default stand-alone widget”.

State description pattern

%.1f °C

Logs

18:52:25.706,"INFO","openhab.event.ItemCommandEvent","Item 'GenvexTemperaturSP_ValueasNumber' received command 21"
18:52:25.707,"WARN","org.openhab.binding.modbus.internal.profiles.ModbusGainOffsetProfile","Cannot apply gain ('0.1 °C') and pre-gain-offset ('100') to state ('21') (formula '21'/'0.1 °C' - '100') because types do not match (towardsItem=false): Cannot process command '21', unit should compatible with gain"
18:52:25.709,"INFO","openhab.event.ItemStatePredictedEvent","Item 'GenvexTemperaturSP_ValueasNumber' predicted to become 21"
18:52:25.711,"INFO","openhab.event.ItemStateChangedEvent","Item 'GenvexTemperaturSP_ValueasNumber' changed from 20.1 °C to 21 °C"
18:52:26.065,"INFO","openhab.event.ItemStateChangedEvent","Item 'GenvexTemperaturSP_ValueasNumber' changed from 21 °C to 20.1 °C"