J. Kissel, F. Clara
ECR E1700123

More yak shaving, but at the end of today's kLog series you'll understand how to execute Daniel's implicit plan in D0902810-v10 for moving cables around to make room for an incoming tip-tilt, aka HTTS, to eventually be named "PM1," i.e. Pop wfs steering Mirror 1.

In this kLog: There're 2x cables DB9 available for the cable run from SUS-R1 to SUS-C4 to cover the needs of that run for PM1, we may not need to buy new cables.

In 2022, I inventoried all optical lever whitening chasses in LHO:63844. In that aLOG I confirmed that the never-existed / now-officially decommissioned HAM2 and HAM3 ISI optical levers were disconnected from their respective optical lever piers.

Today, while poking around the racks, I identified that 
    - The last version of a wiring diagram that had any record of these HAM ISI optical levers was 
        :: HAM3 D1000599-v7 (it's now at -v8, and in O5 D1000599 will be superceded by D2300383). 
        :: HAM2 D0902810-v7 (it's not at -v10).
    - These diagrams disagree with how H1 started cable up the ISI optical levers, which have both the HAM3 and HAM2 ISI optical levers routed to the Oplev Whitening Chassis in U9 (ish) of SUS-R1.
        :: According to the above -v7 drawings, the intent was to have the HAM3 ISI optical lever readout by the Oplev whitening chassis in SUS-R2 over by HAM3.
    - The wiring diagrams specified the 2x long DB9 cable run between the whitening chassis (in the field rack) and the AA chassis (in the CER) to be called
        :: (IFO):OPLEV-HAM2_AA
        :: (IFO):OPLEV-HAM3_AA
    - As H1 labeled them, they're also (respectively)
        :: H1:SUS_HAM2_78
        :: H1:SUS_HAM3_161
    - These HAM2 and HAM3 Whitening-to-AA cables *are pulled* from SUS-R1 to SUS-C4 and SUS-C1, respectively, but they're dangling unconnected to any AA.

In short -- the Oplev whitening chassis S1101555 in SUS-R1 U9 *looks* full populated and in use, but every "other end" of the cables plugged into it are disconnected. This chassis, S1101555 in SUS-R1 U9 can *absolutely* be powered down and removed from the rack, pushed to our spares supply.

So, interestingly to our mission, there's two D9M (at SUS-R1 end) to D9F (at CER end) available to be repurposed.
Coincidentally, according to Daniel's design in D0902810-v10, PM1 needs two D9 cables... sort of.
    - SENSOR CABLE: The OSEM PD output of the SUS-R1 U38 Dual, 8ch satamp, D1002818 is mapped from the "PD Outputs to AA" D9F directly to the SUS-C4 U11 "IN25-28" D0902783 8x D9M input AA chassis.
        :: one of the above ISI oplev cables will meet this need perfectly.

    - DRIVE CABLE: The D1100687-v1 or v2 HAM-A coil driver, which uses the driver board D080276, sends out the four coil drive outputs on a D15F on J4. But, the 4x differential channels can absolutely fit on a DB9, as is evident by the Dual, 8ch satamp, D1002818 which accepts the Coil Drive Inputs at J1 as a D9M. In A+ circa 2021-2022, when we started regularly using this HAM-A coil driver + 8ch Dual Satamp combo, Luis drew up the cable solution to this problem, a custom D15M to D9F cable, D2200034.

        :: So, we "just" need to make a short version of this oft-used custom D15 to D9 cable, D2200034, and then we can use the other cable.

That being said -- Daniel says he's "already ordered the cables." 
Ah HA! But -- I worry that the wrong cable has been ordered -- because in D0902810-v10 page 8, Daniel did the sensible thing and copied and pasted the RM1 and RM2 wiring chains from D0902810-v9 page 8 to create the PM1, and JM1-3 chains on -v10 page 9. But alas, there was a typo on the label of this DRIVE CABLE, citing that it should be D2100747, a D15M to D15F cable. It should be the D2200034 D15M to D9F mentioned above.
So -- if we did end up ordering the wrong cable, here's the solution: With only one short adapter made, we can reuse these D9M to D9F cables for the OSEM PD and Coil Drive cables of PM1, if we want or need. Or anything else future that needs a long from from SUS-R1 to the SUS racks in the CER.

(Future readers beware -- the plan may be to fix the typo D2100747 > D2200034 cable label typo in the D0902810-v10 drawing by keeping the same version number in the DCC but sneakily replacing the files -- so if you're reading this in 2026, the comments about the typos in -v10 may not be there...)