One of the accelerometers on the PSL table (PEM-CS_ACC_PSL_TABLE2_Z) is glitching once per second. The other accelerometers don't seem to have this problem. We noticed this because it was messing up our hVeto results. I searched for where these started, and as far as I can tell it's Apr 14 2:30 UTC (that's 7 PM on Monday local, I think). The onset takes a few minutes. The first plot is an Omega scan from a few hours ago, showing the glitching. The second is a spectrogram of the onset. We are seeing something similar in some of the ISI GS13s (maybe only ones in the center building?). They also have a once per second glitch, though it's not clear if it's related. Detchar will track that down more, and I'll alog it separately.
I have seen large 1 Hz combs in many places at the CS that are due to the Hartman Wavefront Sensor running at 1 fps (the capture rate of 57 at end stations makes a comb of huge peaks in DARM). I think that Ellie is going to keep the HWS off most of the time until we figure out why.
Do you mean a 1 Hz comb in the spectrum, or glitches every second? This is the latter. Do you have an example of what this looks like? Also, is there an easy way to tell when the HWS is on?
We're implementing a Guardian script for ETM HWS control which engages the HWS when we lock, takes a measurement during the initial transient, then turns it off after thirty minutes or so. We'll look into implementing this at the corner station too.
Longer term - we need to look into what we might be able to do to eliminate the camera noise.
The camera can be turned on and off from Beckhoff. The channels you're looking for are:
H1:TCS-ITMX_HWS_DALSACAMERASWITCH
H1:TCS-ITMY_HWS_DALSACAMERASWITCH
There are two channels to look at which are:
H1:TCS-ETMX_HWS_RCXCLINKSWITCH
H1:TCS-ETMX_HWS_DALSACAMERASWITCH