The slow feedback from the green reflection PDH is working again, with the frequency servo on the end station VCOs.  Hopefully this will make locking DIFF easier, since these should help to keep the DIFF PLL within its linear range, which it seems to be doing a reasonable job of right now.

Changes I've made are:

• the ALS guardian is not touching anything in the suspension, and we are locking with the filters used for DIFF locking in place. 
  • this means that the low pass which was previously in the ISCINF filters is now moved to ALS-C_ARMX ect.  The purpose of this filter is to make sure no impulse is sent to the suspension when the history is cleared for the integrators.
• I have also added a second low frequency integrator, replacing the +40dB that was previously in FM1 of the ALS-X_ARM filter module (and triggered by beckhoff).  This gives us more low frequency gain while still keeping our ugf low.
• These changes are in the guardian now.

We need to revist the length to PIT for ETMX at verry low frequencies.  This slow feedback is clearly misaligning the cavity.

Also late this afternoon early evening, ETMX ISI has tripped 3 times.  The plotting script failed,