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Bug #24579

Two cavity operation at CMTF

Added by Shrividhyaa Sankar Raman 9 days ago. Updated 1 day ago.

Status:
Closed
Priority:
Urgent
Start date:
07/01/2020
Due date:
% Done:

100%

Estimated time:
Spent time:
Duration:

Description

  • Unable to control cavity 4 parameters – using controller 2 in the control 1 position.
  • Stopped and started LV when switched to cavity B.
  • Tried connecting to the HWR dev controller in the lab to check this and found the same problems.
  • Ran cavity B in CW mode and applied a FF value of 0.5 and looked at the waveform for control out I and Q.
  • This displays the constant value for FF I and Q seen by the controller.
  • It does not display the entered value for cavity B but the value for cavity A.

History

#1 Updated by Shrividhyaa Sankar Raman 9 days ago

  • Priority changed from Normal to Urgent
  • Searched through the firmware files for possible error locations based on the output observed from DACs 1 and 3.
  • Checked to make sure the registers being written to are the right registers, by comparing the Debug output from the ARM code, the spreadsheet and the firmware.
  • Checked to make sure the right signals were received on the DACs (using the scope) upon changing the values on LabVIEW.
  • Noticed value of Magnitude on Cavity A is mimicked by value of Magnitude on Cavity B. This change takes effect only when the phase value is changed.
  • TODO:Check to see if this is a LabVIEW issue.

#2 Updated by Shrividhyaa Sankar Raman 9 days ago

  • % Done changed from 0 to 100
  • Labview checked but processing of parameter in question was not made for that parameter but for a derived parameter.
  • Checked for callback function of the derived parameter from the spreadsheet.
  • Callback parameter CHANGE_cb_CB_ff_magphase converts the Mag and Phase to I and Q.
  • Code computed using wrong variable.
  • Correction was made and tested with Labview.
  • Issue was corrected!

#3 Updated by Shrividhyaa Sankar Raman 9 days ago

  • Status changed from New to Closed

#4 Updated by Shrividhyaa Sankar Raman 1 day ago

Once the issue was corrected and tested at the lab, the code was taken to the CMTF facility and tested there and was found to work.



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