J. Kissel

Stuart recently discovered that the SR3 optical lever got overlooked during the big SUS HAM 5-6 Computer swap to accomodate new suspensions related to the SQZ upgrade (see IIET ticket 9928).

Daniel and I brainstormed several different possibilities after browsing through the HAM3-4 and HAM5-6 SUS wiring diagrams (D1000599 and D1002740, respectively):
   (1) Buy a whole new ADC card  for SUS HAM 56 computer (and associated ADC Adapter Card, Cabling, and AA chassis)
   (2) Plug the signal -- no matter how icky it is in analog -- into some other suspension's spare spigot
      (a) The SUSHAM3-4 control chassis has a few spare DB9 ports (especially after the decommissioning of HAM table optical levers)
      (b) The SUSHAM5-6 monitor chassis has one spare DB9 port

After discussing with the systems group, they suggest nixing (1) in favor of (2) for the time being (i.e. until A+). Having no preference for (2)(a) or (b), they suggested looking at the physical location of the cables and ports in the CER to break the tie.

I attach pictures of the relevant racks.

I had initially thought -- based on the pictures -- we should obviously go for (2)(b): plug the SR3 optical lever DB9 into the spare DB9 port of the SUS-C8-38 AA chassis, which feeds into channels 4,5,6, and 7 of ADC 2 of the monitor chassis. Once in the susauxh56 monitor model, we would then ship the signals over to the h1sussr3 control model via Dolphin PCIe inter process communication, as had already being done during O1/O2 via the h1sussrm model.

HOWEVER -- I remember that the AUX monitor IO chassis / computers don't have a Dolphin PCIe cards installed, and Dave confirms this. He also confirms, however, that adding a new card to the IO chassis is a small expense -- but only if we're not short on Dolphin PCIe switch ports.

The HAM3-4 racks are on the other side of the "hall" of racks, so it would be possible to connect in that control chassis (which does already have Dolphin PCIe capability) re-routing the cable over to that rack and into the appropriate chassis.

So, again, both options in (2) are a toss-up requiring a bit more information to decide between the two. I'll update the ticket, file and ECR, and wait for further discussion with a few more people before making the decision.