Reports until 13:41, Tuesday 07 February 2023
H1 ISC (CAL, CDS, DetChar, ISC)
jeffrey.kissel@LIGO.ORG - posted 13:41, Tuesday 07 February 2023 (67267)
OMC DCPD Signal Chain Cleanup in Field Rack ISC-R5
J. Kissel

Now that the dust has settled with the OMC DCPD's 524 kHz signal chain (we're now happy enough with it that reverting seems worse than debugging what problems we may find going forward), I've:

    :: Removed the former, and no longer connected at all, D2100631-style "4x channel 2x OMC" OMC DCPD whitening chassis S2101608 from ISC-R5 and brought it to the EE shop for post-mortem characterization and retirement. It's location *was* in U-height 26 (see, e.g. it pictured in LHO:66986), and now that slot is vacant.

    :: Removed the temporary y-cable (installed in Dec 2022; LHO:66330) that split the output of the OMC DCPD whitening chassis (regardless of D2100631-style or the newer D2200215-style) towards both 
        - the former, lsc0 -- the "65 kHz," 16-bit ADC, crowded -- IO chassis as well as 
        - the new omc0, -- the "524 kHz," 18-bit, low noise ADC, segregated -- IO chassis
    from the signal chain, such that now only the path to the new omc0 IO chassis is connected via a DB9 cable labeled H1:ISC_426 (whose other end meets the omc0 AA chassis in the CER). The y-cable is still connected to the cable for the path to the lsc0 IO chassis, dangling unconnected between the racks. 

Pictured below is the "before" removal of the y-cable in IMG_9304.jpg, and "after" in IMG_9305.jpg showing H1:ISC_426 neatly connected to the "To AA/ADC" port of the new D2200215-style whitening chassis, S2300003.
Images attached to this report