The commands which move the arm locking to the low noise boards have been added in the locking sequence. The activation is performed soon after the acquisition of dark fringe. No major problem has been observed concerning the stability of locking and alignment.
This morning two specific new states have been added tin ITF_LOCK to deal with the low noise transition :
- ACQUIRE_LOW_NOISE_1
- LOW_NOISE_1
Those states are including the commanding to the coil relays switchboxes and implement:
- the delay between Marionette reallocation enabling and Low Noise enabling in the DSPs (low_noise_ramp parameter in ITF_LOCK.ini)
- the delay between Low Noise enabling in the DSP and switchbox relays in Open mode setting (open_relays_ramp parameter in ITF_LOCK.ini)
The corresponding new code has been loaded and the commanding to the switchboxes verified. Transition to LOW_NOISE_1 will checked as soon as ITF will allow.
The new path has been tested throughout the evening, and after a couple of minor tweaks it worked very reliably.
The adjustment of the UGF lines' amplitudes (DARM, MICH and PRCL as of now) has been added to the LOW_NOISE_1 configuration, with tentative (lower) values saved in the configuration file, to be tested during the next full lock.