Modbus Power Readout scale factor Multiplus II GX

Modifications
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1

Hi Community,

I´m operating Victron Multiplus II GX and connected via Modbus to my home automation system.

Works fine for me. Just one question, maybe for optimization. I use register 12 and 23 to read out die Input Power and Output Power of Multiplus device. Due to the scale factor, it is only possible with ten digit readout (10, 20, 30, 40,….). I would like to be more precise and want to read out the power to the last digit (11, 12, 13…).

Any ideas how to approach? Is the maybe another register to process?

Thanks

Sebastian

com.victronenergy.vebus Input power 1 12 int16 0,1 -327680 to 327670 /Ac/ActiveIn/L1/P no VA or Watts
com.victronenergy.vebus Output power 1 23 int16 0,1 -327680 to 327670 /Ac/Out/L1/P no VA or Watts
2

I don’t believe that the internal current measurements, and therefore power measurements, are more precise than that.

3

yes, maybe. But on the Victron dashboard, everything is shown with more “precision”.

Are these values available?

4

Your problem is to read out modbus, correct ?
You can get stacks of 10 but you dont want to read them out one by one ? Thats not possible with modbus imho.

What dashboard are you talking about ?
If you are talking about the Dashboard from your local CERBO GX did you tried getting the values with a web request ?
Should be available.

5

No, just talking about the scale factor of 0.1

Therefore I only receive values like 200, 210, 220 Watts. With scale factor of 1 it can be like 205, 212, 223 Watts.

Dashboard of Multiplus itself or VRM dashboard. In both cases, the values are available with scale factor 1.

6

With the Victron integration under settings, System grid L1 and System consumption L1 I can read the values you are looking for.

System consumption L1

System grid L1

7

okay, which Modbus registers you are talking about?

8

Probably not available on modbus, as implementing floats in modbus isnt that easy. think they just stripped of or rounded the last digit. why do you need it that exact ?

9

So it sounds and looks like they do have the precision internally, but the modbus registers do not expose it, which is disappointing.

10

ok, thank to all.

Sound that I have to deal with that. Idea of improvement just was for optimization and fun.

11

Depending on your needs, the Victron integration and Modbus TCP already offer you quite a few options.