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Problems with measures of MKM34Z256VLL after calibration

Question asked by Raphael Camargo on Dec 14, 2018
Latest reply on Jan 11, 2019 by Jing Pan

Hello,

 

I work in V2com and we are developing a Three Phase Meter using the MKM34Z256VLL7 and following the NXP guidelines (Three Phase Power Meter Reference Design|NXP) we are using the original Firmware of this board (Three Phase Power Meter Reference Design|NXP  file:project.bin), and the suggested software to read the measures (FREEMASTER), the file of FREEMASTER that NXP support gave to us (monitor.pmp) and the steps to calibrate suggested in the document of this meter (https://www.nxp.com/docs/en/application-note/DRM147.pdf  DRM147.pdf - page 20).

The problem is: before the calibration,  we can measure the signals in the inputs (These are shown in the attached image freemaster_before_calibatrion image and Free\Master labels them as U_RMS_Ph1 and I_RMS_Ph1) and after the calibration - watching the same two signals - we see the value remain seemingly static, at levels nearly zero, regardless of how much we increase or change the input signals (in other words, we change the load but the submeter does not meter or aggregate any usage) (this is shown in the attached image freemaster_after_calibatrion). How can we get the right measures after the calibration?  How can we see and verify the submeter is properly metering the current load after the calibration?  Should we be setting breakpoints  in the firmware?  Or should we be watching certain variables in FreeMaster?  We believe we have monitored all the available variables in FreeMaster and it appears the calibrated submeter is not able to detect or measure the load.

 

We are blocked in our development of a product and need your help.

 

Thanks

Raphael

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