What value do I measure with "L1" compared to "L1-N" and "L1-L2", according to the protocol specifications? What value do I get via "L1"?

[ZvonimirRaic]

Ciao,

It is not clear to me, looking at the specification of the protocol itself, what value is measured with the variable/value "L1"? Shouldn't "L1-N" be used to measure the phase voltage, if the current is measured it would be clear to me, so I don't know what is measured across the phase with the value of L1 and what measured value we get only with L1, except for the marking of the first phase of a three-phase system? If there is no potential difference on L1 itself, what does the result of that value represent, in relation to voltage, current, power?

The question was about this function below:

addMeterValueInput({return (int32_t)33;}, "Energy.Active.Import.Register", "kW", "Body", "L1", 1);

I noticed this and by looking through earlier queries I was unable to find out #110, #185.

I would like to know, so if you can help me then know how to better define the values ​​related to phase AC measurements, for better diagnostic settings?