In order to compensate the drifts of SF/BF-GAS due to the pumping down from the last Friday, I changed the keystone positions by the fishing rods. Consequently, I could not reproduce the situation just before the pumping down: Currently both the GAS-keystones are away from the center of the linear range though, if the SF/BF-GAS filters go to better position (i.e., close to the center of the linear range), the IM-OSEM signals go away from the optimal positions.. which is the position to be referenced..
This is to be investigated more.
In any case, position control filters for the GAS filters were implemented, the keystones were sticked at the position which looked better than today's starting point. Its long term performance is to be checked.
[Note]
The guardian for the PR3 failed to turn on the BF vertical control successfully again, even though the control worked properly when it was tuned on by hand. The script is to be reviewed again.
= PR3/PRM GAS/BF-LVDTs =
I found that the setting of the function generator was not correct: somehow it had been sending square wave instead of sinusoidal wave from just before the pumping down. This made the GAS signals become messy. After revising this, it was found that the keystone height was not too high/low.
[Note]
Since IM was sitting in the frame, the (SF/)BF-keystoen height was changed again so that the IM swinged freely.