To run the test that calculates how much loss we have between the ASC-AS_C (anti-symmetric port) and the DCPDs at the output of the OMC (where strain is derived from).

1. This test is set up to run in NLN.
2. Turn off OMC ASC. Go to sitemap -> OMC -> OMC Control and note down the MASTER GAIN value in circled section in attached photo, then change this value to 0.
3. Go to /ligo/gitcommon/labutils/darm_offset_step and run:

conda activate labutils

python auto_darm_offset_step.py

The script turns on one notch in the DARM LSC loop, then changes the PCAL line heights so all the power is in just two frequencies.

At the end it reverses both these changes.

It can be stopped using Crtl-C but this will not restore the PCAL line heights back to their default values so you may have to use time machine.

After setting up the PCAL the script steps the DARM offset level in 120 s steps, I think it takes about 21 minutes to run.

After the script finishes, please put the OMC ASC MASTER GAIN back to its original value.