Ohm to Celcius and Pulse Counter

I have a new installed Openhab 3 with an Velbus binding, everthing is working fine but at two things i need some help.
First the VMB4AN on these device there are two Pt1000 conected, the VMB4AN delviers the Ohm from the Pt1000, and i am to stupid to get it in Openhab to recalculate it in Celcius.
Second a VMB7IN delivers a pulse counter but the widget shows only the numbers to the dot → 1 in real 1.34 ore 0 in real 0.11, again i am to stupid to find it where i can change it.


There is a formula here PT100 Calculator | Fluke Calibration

I guess if there are any enterprising coders out there, someone could contribute a standard transform for OH for converting UoM ElectricalResistance (Ohm) to UoM Temperature (Celsius) values for the most common standard resistance sensors i.e. Pt100, Pt1000, Ni1000 at least.

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Thank for replay
i know these page i have tried todo these with blockly …anyway



Welcome to openHAB, I hope your Velbus system is working well.
If there is anything you need, please just ask.

With regards to your conversion requirements, I can tell you how I’ve achieved something similar.

I created an orphan item and a rule.

The rule is triggered by every change of the VMB4AN or VMB7IN item.

The formula is applied to that value and saved to the orphan item.

You can do the same thing in Node-Red or Blocky.

That said, I’ve re-read your post.

Did you know that this can be done within the configuration of the VMB4AN?

You just need to calibrate the sensor R values to the corresponding °C value, using the correct tab.

Then the value you see in openHAB will be the temperature.

Something similar can be done with the pulses in the configuration of the VMB7IN, as long as you’re wanting

(And something else that I can’t remember without looking at the VMB7IN config page)


hmm on the Switches in Velbus i can see the °C.
Witch Tab in VelbusLink do you mean.

in Oh3

With the VMB7IN i have the only problem on the webpage

it shows only the 0 or the 1 everthing without dot and the follwing numbers

thx Markus

That looks correctly set to me.

Oh, I see what you mean.

I’ll need to test this when I get back to my office.

In the mean time, maybe one of the Velbus binding developers can help shine some light on why your seeing the raw value and not the converted UoM value.