Since we have to relock, I've switched the order of items in lownoise length control, so that we will change the main LSC gains first, then turn on the FF. Hopefully that will address the issue that Daniel hypothesises is our problem, and we won't ring up the 102 Hz line. If this does not work, do something like an
svn up ISC_LOCK.py
in the userapps/isc/h1/guardian/ folder to reveret to the previous file (which I had checked in just before I made this mod). I have not checked in ISC_LOCK.py with this modification yet.
This *may* have helped, in that the resulting 102 Hz line was smaller during this relock.
This is a quick comparison plot of DARM around 102 Hz from the relock we just had (with reordered guardian steps), and the previous relock with the normal order of guardian steps. Both times I chose are the times when the guardian state number changed to 600 (entering nominal low noise).
Since this seems to have worked (at least it didn't hurt / we were able to lock), I have now committed this to the svn.