M. Todd, S. Dwyer

I'm sure there are other sources for this instruction set, but it will serve me later having written this out -- lending some muscle memory hopefully. We are interested in taking several OMC scans over the next couple weeks to estimate mode-matching of various cavities to the OMC in comparison to our models.

Step 1: Suspension Settings for the TMs and PRM/SRM:

Going to sitemap > ASC > IFO Align Compact , you can find shortcuts for each of the suspensions. We will want to take both the ETMs to misaligned as well as the PRM and SRM. If we want to do a single bounce with ITMX, we misalign ITMY and vice-versa.

To misalign an optic from IFO Align Compact, click on the full optic suspension shortcut with the corresponding optic name (e.g. overlapping squares + "ETMX"). At the top of the suspension screen, take the guardian state to misaligned. 

Step 2: Turn on ASC centering loops for the OMs

Going to sitemap > ASC > ASC Overview > DC Centering (middle screen), turn on the inputs to DC3 and DC4 pitch and yaw loops.

Make sure that the inputs to the centering loops start to go to zero and the outputs are not blowing up to infinity.

Then go to sitemap > OMC > OMC Overview > fast shutter and ensure that the status reads open, otherwise, hit open.

Step 3: Turn on OMC ASC and set gains and offsets

Going to sitemap > GRD > ISC Overview find the OMC guardian and take it to ASC_QPD_ON

Going to sitemap > OMC > OMC control, set the MASTER GAIN to 0.02  and bring the LSC offset to the far left ( -50.0 ). 

Step 4: Go out and turn off the sidebands (9, 45, 118 MHz)

Going out to the PSL racks, in the far right stack towards the bottom find the EOM drivers labeled 9MHz and 45MHz and flick the switch on the panel to OFF

Then below the RF Combiner Amplifier, unplug the cable going to the BNC port label 118 MHz.

Step 5: Run OMC scan

An example can be found in my templates /ligo/home/matthewrichard.todd/Templates/omc/20251006_OMC_scan.xml

Open the template with DTT and save it as another copy, naming it with whatever date you are running it plus any notes.