J. Kissel, S. Aston

Just in case people were not aware, after the recent install of an expansion pack of violin mode damping filters on the QUADs (see LHO aLOG 42752, ECR E1700286, and IIET ticket 8759), Stuart and I have identified that this some how has insidiously interacted with the binary I/O switching of the coil drivers, see LLO aLOGs 39653 and 39717.

I plan to revert violin mode filter expansion code tomorrow, but that means for now (and since July 3rd 2018) we haven't had truly functional R0, L1 (UIM), or L2 (PUM) actuation on the Test Mass suspensions (QUADs). To be explicit, this affects all QUADs: H1 SUS ITMX, H1 SUS ITMY, H1 SUS ETMX, and H1 SUS ETMY. Attached is the screenshot of how it manifests: a *few* of the coil driver's TEST/COIL enable switches are pushed to TEST, so that the analog input to that driver channel is a terminated resistor, a la L1200193 instead of the requested DAC signal.

I'm happy to revert sooner if we feel it's needed, but the crowd in the control room at the moment, didn't think it was necessary to accelerate the revert faster than tomorrow.

You can track the bug and hopefully its fix via the new IIET Ticket 11066.