Energy Meter VM-3P75CT Voltage between Phases via Modbus

Modifications
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1

I want to read the Voltage between Phases via Modbus of an Energy Meter VM-3P75CT. I am already reading Data from my MK2 and Cerbo CX but I don’t have the Info about the registers where I can read the information?

In Victron Connect I can see the EnergyMeter and there I can also see the Voltage between two phases. So it is measured, I just need to know in which register it can be read.

Thanks!

2

If you mean using ModbusTCP, have a look at the Victron source code on Github here.
I’m not aware of a published register map.

Based on some testing I’ve done, I can tell you unofficially that the voltage registers and scale factors are:

# 0x3040  L1 Voltage         0.01 V
# 0x3048  L2 Voltage         0.01 V 
# 0x3050  L3 Voltage         0.01 V
3

Okay thank you. These are also easy to get with Cerbo GX and NodeRed. But the Voltage between two phases (400V)?

4

Those are voltages from each phase to neutral.
I don’t see any registers with line-to-line voltages in the code (they may exist though).
EDIT: yes I do, they are are at 0x3046, 0x304E, 0x3056

I have not looked at them, and I don’t know which line pair is which, but I would guess L1-L2, L2-L3, L3-L1.

If those registers don’t work,
Maybe take each pair of L-N voltages, average them, and multiply by sqrt(3) for three-phase? Like sqrt(3) * (L1 + L2) /2 for L1 to L2 voltage?