JAC Heater ran out of range this afternoon and the JAC unlocked. We started this lock stretch (first x cursor) already at a pretty high PZT offset so I might add a upper limit to how high a voltage we should lock at.
I have increased the gain magnitude in the heater control servo from -0.1 to -0.15 to try and stop this happening again before this evening when we will increase the power set value from 1.5 W to 3W to give us more headroom above ambient temperature for the servo.
Here is a plot including the control signal. With the lockloss at the first cursor and the gain change at the second.
The JAC locked again at a much lower voltage and so stayed locked until the planned increase in the set power to 3W last night caused some locklosses.
The system looks underdamped from this step response so I will test some changes to the controller over the weekend.
I aaded an upper limit to the SCANNING state in the JAC_LOCK guardian it will only scan up to 300V instead of 330V, this should prevent the cavity locking near the upper limit of the PZT.
Loaded and committed the guardian.