The waveform is represented as an array of 32-bit floating point numbers with a length of 128 entries per cycle.
The electrical voltage value in the parent route is calculated by performing a root mean square (RMS) of the raw waveform.

Why is the peak-to-peak voltage in the waveform higher than my panel voltage?

This is because in an alternating current, the voltage is calculated by taking a root mean square (RMS) of the raw waveform. So if your panel voltage is 120V and assuming a pure sine wave, it is normal to see a peak-to-peak range of 168V to -168V in the raw waveform.

To calculate the RMS voltage, take the peak-to-peak voltage (168V to -168V = 336V) and divide it by 2√2 (≈2.8) to get the RMS voltage: 336 ÷ 2.8 = 120.