[Dsg-halld_plc] [New Logentry] Follow-up Re: Inoperative magnetometer reading partially troubleshot

[beng at jlab.org]

Logentry Text:
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We performed the verification step of the calibration procedure for the ADC module, this passed. Since doing this test requires swapping out the terminal block we figured that might have been the problem.

The cables were swapped one-by-one onto the new terminal block, the PXI was rebooted, still bad B_Field reading.

Okay, maybe the ADC is bad after all? We swapped that out, now in addition to the B_Field reading being bad the I_Shunt reading got worse (from just slightly negative to -10 A).

Our first clue! It looks like the offset/slope for the channels is incorrect. Low and behold when logging into the PXI the file was changed around when it went bad.

[figure:1]

I manually changed the file to have the same value from the config file on GitHub (which has never changed [went from an offset of -2.509762 to 0.000553]), but all that did was make it positive instead of negative. So there is still some more troubleshooting to do, but we've made some progress and for sure we should run the PXI calibration function the next time the MPS is powered on to get more realistic offsets.

Also, since someone probably hit this button when there was some field which is why it's reading bad, maybe this should be moved to somewhere less easy to get to?

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