Description:

• current gain = 700000
• phase for damping filters still at +30deg phase
• phase for PLL phase channel is -36deg, started at -30deg phase this morning
• PI drive out signal is going on and off, though the PLL appears to remain locked
• PI drive out signal is at most +/-400 when it is on, more typical value is +/-200
• gain has little effect on PI drive amplitude at this point - a limiter somewhere?
• amlitude of the peak in OMC PI is hovering around 630
• before this, when PI drive out signal was staying on all the time, I noticed that anything less than +/-400 counts on the signal did not damp, just maintained the RMS
• when I increased gain there would be some reduction of the RMS, but it wouldn't continue, so I'd raise the gain again, same effect, until the PI drive signal started going on/off
• is seems like raising the gain this high might have triggered some protection limit, but lower gain didn't damp, so mode 26 cannot be effectively damped

The one change I did not try was to change the bandpass filter back to FM1, where it was a week ago, from FM10 where it is now.

Plots attached:

• plot 1: PI mode 26 RMS (cyan), around 0.235
• plot 2: PI drive to ETMY (purple), going on/off
• plot 3: PI modes 26 (cyan), 27 (red), and 28 (gray), for comparison, all on the same scale
• plot 4: peak at 15009.6