HAM4 and HAM5 have had strong glitches for the past several weeks (sorry if I missed this being reported already, I didn't turn it up in a search, we found these by accident). They are sometimes completely not there, but sometimes happening as fast as twice per second! Attached are a slew of plots taken roughly every two days for H1:ISI-HAM4_BLND_GS13RZ_IN1_DQ (but I also see the same in H1:ISI-HAM5_BLND_GS13RZ_IN1_DQ). 

We don't have a good lead on these, but wanted to report. They look an awful lot like what we have seen before when the HWS camera was on, see e.g., 18531. I noticed a note in the log on August 25 "15:54 Elli – Going to Hartman table at HAM4", and I also noticed that the glitches started showing up after a long hiaitus around August 27th. However, if I have my sign correct (0=off) for the camera switch channels, then the HWS cameras in the central station are currently off in O1 running.  

Assuming it's not HWS, we should probably check ISI actuators for DAC glitches or overflows.