Question
I am looking for some details on the LAENERGY register of the ADE7754.
Is the power(w) calculated from the energy stored in LAENERGY?
Answer
The value stored in the LAENERGY register is energy accumulated over a fixed
number of half-line cycles (set by LINECYC (13_hex) register). For example,
in 50 Hz system and FFF_hex written to the LINECYC register, the LAENERGY
register will be updated with the amount of energy from 4095 half line cycles
(40.95 seconds). You will know that there is a new value in the LAENERGY
register by setting the LENERGY bit (0A_hex) in the IRQEN register (0F_hex).
This will cause the IRQ pin to go active Low at the end of LINECYC number of
half line cycles. During calibration, you should determine the number of watt
hours per LSB so that you can convert the reading from the LINECYC energy
register to Watt hours.
Pages 22-23 of the datasheet describes some detail about using the LAENERGY
setting on ADE7754.