General:
Last week, the ISI, SUS and HEPI models-screens were updated to receive the last features and to replace the EPICS connection between the SUS and SEI watchdogs by the reflective memory (BSC6). The dolphin connection (SUS-SEI) will be added on BSC8 next week. The safe snap shots were also updated.

Ramping functions:
Both isolation filters of the ISIs and HEPIs can now be ramped using a function launched from MEDM. A restart procedure is currently being written. The DCC # is E1200762.

ISI Control:
I have changed the compensation filters of the output filter bank of ISI-BSC6 and ISI-BSC8. The cut-off frequency of the compensation filters was lowered 2 weeks ago (losing 6 degrees of phase at 30Hz). By the time, the watchdogs were tripping when engaging the boost filters. The “Turn on” option of the boost filters was changed from “zero crossing” to “ramp” (10s). The current filters are the initial ones.

I have introduced the T240 in the stage 1 blend of the 2 ISIs. The isolation provided by stage 1 using the T240 in the super sensor is higher (factor 5-6 @ 2Hz) than with L4Cs in the blend. During a quiet period, several configurations were tested. I have attached some results of few measurements on ISI-BSC8:

The first plot ITMY_T240_Y_2012_08_14_aLOG.pdf shows the non calibrated ASD of the stage 1 velocity (measured by the T240) in the Y direction with the different configurations:
- Damping only
- L4C X-Y-Z blend at 250mHz; L4C RX-RY-RZ blend at 750mHz; No Isolation on stage 2
- T240 X-Y-Z blend at 250mHz; L4C RX-RY-RZ blend at 750mHz; No Isolation on stage 2
- T240 X-Y-Z blend at 100mHz; L4C RX-RY-RZ blend at 750mHz; No Isolation on stage 2

The second plot ITMY_GS13_Y_2012_08_14_aLOG.pdf shows the non calibrated ASD of the stage 2 velocity (measured by the GS13) in the Y direction with the different configuration:
- Damping only
- L4C X-Y-Z blend at 250mHz; L4C RX-RY-RZ blend at 750mHz; No Isolation on stage 2
- T240 X-Y-Z blend at 250mHz; L4C RX-RY-RZ blend at 750mHz; No Isolation on stage 2
- T240 X-Y-Z blend at 100mHz; L4C RX-RY-RZ blend at 750mHz; No Isolation on stage 2
- T240 X-Y-Z blend at 100mHz; L4C RX-RY-RZ blend at 750mHz; Isolation on stage 2 – 750mHz blend
- T240 X-Y-Z blend at 100mHz; L4C RX-RY-RZ blend at 750mHz; Isolation on stage 2 – 250mHz blend

Blend switcher for the ISI:
The blend switcher allows changing blend frequency and type (CPS-L4C blend or CPS-T240-L4C blend) on the fly. It's working well. However, the isolation filters still have to be ramped up with the CPS-'L4C in the blend since the T240s saturate in the ramping process due to the small initial DC offsets (with the reference position) of the platform.

HEPI:
The blend and isolation filters controlling the pringle modes were reintroduced. The transfer functions used for sensor correction are linked below:
- H2_HPI_ETMY_H2_HPI_ETMY_TF_STS2_To_L4C_2012_07_03_044933.fig
- H2_HPI_ETMY_H2_HPI_ETMY_TF_STS2_To_L4C_2012_07_03_044933.pdf