Sheila logged that the two lock-losses on Tuesday were caused when her excitation measurement on the PSL ISS THIRDLOOP SERVO was both aborted and when it completed correctly. It would appear that this is due to the filter being used by the excitation has a slow ring down and it was outputting a non-zero value when the awgtpman killed the excitation. This caused a sharp transient step which in this case resulted in the output of the THIRDLOOP_SERVO filter going very high.

This problem was initially reported by Jenne in this alog. My analysis was reported in this alog. Daniel, Jim and myself came up with a work-around described in this alog  and in this wiki  

To verify the filter in this case has a long ring down, I ran it on a test stand front end, it does indeed have a long ring down, image is attached.

I had opened FRS8368  for this issue, which can now be closed.