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Intermittent dropout of RMS measurements

Question asked by kdavies4 on Nov 7, 2017
Latest reply on Jan 18, 2018 by kdavies4

We are seeing an intermittent dropout of data on the AVRMS and AFVRMS registers. We are validating the CRCs and the line A period measurement remains stable, so it does not seem to be an issue with the SPI communications. Are there any reports of issues with this?


Could you explain the period over which the AVRMS and AFVRMS values are calculated? The datasheet states that these signals are filtered and updated at 8 kSps, but there is no discussion of how many cycles the data is measured over (or is it even synchronized to line cycles at all?). 


Also, the registers for THD (AVTHD, AITHD, etc.) are returning 0 even though there is some harmonic distortion when calculdated from the RMS registers (AVRMS, AFVRMS, AIRMS, AFIRMS, etc.).