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QPC Controller Issues, Improvements Incoming

Mitchell Cabral We contacted Gamma Vacuum regarding issues with long-run QPC controllers and their noisy signals in August. This led to a meeting with Edwards Vacuum, their partner company, where we discussed a temporary solution to update the firmware with an unreleased version. This unreleased firmware was also being used to solve similar issues in Germany as well as the Accelerator Department. In October, we updated the firmware on B940:009:R03:PCI:01 inside of the FEE. This improved the stability of the pressure report on two of the three working channels, however there was still some variance in the third channel. 

A second ongoing issue that was not solved with the firmware update, is the inability to run all four QPC channels at once without error. Three channels can run properly, but once the fourth channel is active, all four channels will enter an error state. This topic was discussed with Edwards as well, but the fix is replacing the CPU chip. All QPCs with this error must be sent back to Edwards so that they can replace this chip, then resent back, but this is not possible with supply-chain issues and critical dates for beam. We are pushing to get new QPCs that were order last year to arrive sometime in October or November so that we can replace these controllers and send the defective ones out to be fixed.

Mike Estrada anything to add/fix to this QPC section?

MEC-U

Jing Yin 

LCLS-II-HE

Margaret Ghaly 

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