HI everybody...

Introduction:
This is Venkatesh...and i'm doing a power quality meter using a ade7754 chip. I have bought a ade7754 evaluation board and i'm getting familiarized with the board using a evaluation software that analog devices has provided.

Aim of the experiment:
Get a value in the RMS register which corresopnds to the input given.

What i have tried doing:
1) Connected a 230VAC supply to Rphase. and recorded the value in the corresponding rms register(Before connecting any input-->ie.0VAC i had a junk value in the RMS register. I did not attempt to correct that using AVRMSOS register as i read in the documentation that the AVRMSOS registers must not be calibrated when input is nil)..I got a value in the RMS register. THen i connected 20VAC to the RPhase input. and i recorded the rms register values.

2) I used the formula
VRMSOS = 1/64 * ((V1*VRMS2)-(V2*VRMS1))/(V2-V1)
I put this value in the VRMSOS register. Then i recorded the value i got in VRMS register.( The offset i got was a very low negetive value ...something like -9.231..and i think it will not make much difference).

3) I tried Vrms/LSB formula but i did not get the required results.

4)Can anybody help me out regarding how to get value in the RMS register which corresponds to the input given. Also How can we nullify the rms register values when there is no input.

Thanking you
Venkatesh