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ADE7880 - How to set up for phase Harmonics monitoring / calculation

Question asked by karens on Sep 30, 2014
Latest reply on Oct 3, 2014 by hmani

Hello,

 

I have questions regarding the setup for ADE7880 harmonics calculation

 

1. VLEVEL register value calculation

 

On the equation 22, rms value of the phase voltages when the ADC inputs are at full scale, is this value upon the phase voltage gain setting at Gain register? On my application, phase voltage gain is set to gain of 2, then should I use 250mv as the full scale peak value or use 500mV (gain of 1, as the default on Gain register) on this equation?

 

2.  On page 65, section "Configuring Harmonic Calculations Upodate Rate", it mentioned that ADE7880 calculation takes typically 750ms to settle within the specification parameters. Is this the one time settling time, happened only if some harmonic calculation related setup is changed, or right after harmonics calculation during the power up initialization? In other words, during the normal operation, there is no such settling time as long as no harmonics calculation parameters change, is it right?

 

Typically, if I need to switch the phase to monitor, e.g switch from phase A to phase B, I must wait this 750 ms after changing the phase selection, in order to get correct value, is it right?

 

3.     On my application, CF2/HREADY pin is connected to MCU external interrupt pin. So can I just reply on this line to detect if the harmonic data is ready for read, ignore bit 19 setting of STATUS0?

 

Thank you very much for the help.

 

Karen

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