Sheila Terra Evan

This afternoon we made some progress on things that were making locking difficult, and only a little progress on getting to low noise.  

• DRMI asc engaging changed a little (the input for the MICH ASC filters is turned on earlier) so that the guardian can now be allowed to run without intervention and turns on MICH, PRC2, INP1 loops.  
• Added a state to ISC_LOCK (ADJUST_OFFSETS) that adjusts the POP and MICH offsets to that is currently used after powering up to 50 Watts.  We tried to move the offsets before powering up, but found that at 2 Watts these offsets reduce the recycling gain. 
• Fixed a problem with the way the ISS 3rd loop was turned on that meant guardian did not recognize some locklosses.  (This caused unforseen problems and cost us some time, but is fixed now.)  The third loop is now handled by the IMC guardian. 
• ITMs are using offloaded control now, for some reason the ITMs and ETMs had been different.  This is accepted in SDF. 
• We rearranged the order of some guardian states, and took PREPARE_ISS out of the coil drivers state.  (We need to do low noise ASC before we swtich coil drivers if we are adding the quad switching to coil drivers.)
• We found that LOWNOISE_ASC did not work because for some reason the gain at high frequency of the 40 Watt compensation in CHARD P was -10 dB, while it should have been 0dB.  This seems like it must have changed since last time we used this state, the rest of the 40 Watt compensation filters were fine, with 0 dB at high frequency.  
• With this fixed we could do the first several steps of lownoise ASC, but broke the lock at the end.  I am not sure why
• PI stuff has been good tonight, we are going to leave the IFO locked at 50 Watts in a high noise state.