Hi Don,

I think the issue is the range on the channel. The voltage channel has 2 available ranges – 60V and 600V. I think you’re in the 60V range and the channel is saturating, which is why you’re seeing the RMS peak out around 85V.

With your initialization commands, add
CH2:RANGE_I range 1 (code 31, byte 1, assuming 147xxx firmware)

Best
~James