J. Kissel for D. Sigg, E. von Ries

Daniel is slowly but surely building up a basic control (well, drive and readback) system for the lower (M2) stage PZT actuator of ZM2, ZM4, and ZM5, which are all the HAM Piezo Double Suspension (HPDS).

In this entry, I cover the changes he's made to the corner station TCS front-end model, h1tcscs.mdl, which lives on core 7 (specific_cpu = 8, DCUID 26) of the h1oaf0 machine, and drives a 16-bit DAC in the correspondingly named IO chassis.

The PZTs on the M2 stage are just a single, longitudinal actuator inside the barrel of a metal optic holder that pushes on the back side of a modular, curved, pre-loaded, mirror/optic clamped to the barrel (you can find the designed radii-of-curvature after pre-load in T2000101). Thus the drive changes the radius of curvature of the optic and can be used to change the mode-matching of either the beam going from the OPO to the new Filter Cavity (FC) via ZM2 OR to mode-match the filter-cavitied SQZ beam to the IFO via ZM4 and ZM5. Each are driven by a *fast* DAC channel, through an HPDS concentrator D2100449, then through a Aplus Dual Strain Gauge and HV Piezo Driver D2000555, because we want to explore options for *dithering* the radius of curvature at ~40 Hz.

Thus, in the corner station TCS front-end model, h1tcscs.mdl Daniel added four filter banks hooked up to the first 4 DAC channels of the second (and *only* 16-bit) DAC card in the oaf chassis, which result in filter bank channel names that one can use to send and AC excitation and DC offset,
    H1:AWC-$(OPTIC)_PSAMS_DRV_EXC,
    H1:AWC-$(OPTIC)_PSAMS_DRV_OFFSET,
    
respectively where $(OPTIC) is ZM2, ZM4, or ZM5.

Erik installed this model change for Daniel today, and pushed a DAQ restart as well.

I'm continuing to work on building up and MEDM screen for HPDSs after the standard fashion folks to use.