Corey, Kiwamu,

FSS does not lock on its own as reported Cheryl (27108). In addition, this morning we found that the range of the temperature scan was not good at all so that the autolocker was not finding a 00 mode at all. We have changed the range from [-0.025 K, 0.00 K] to [0.00 K, 0.025 K]. This improved the situation, but the FSS autolocker still keep failing the acquisition.

As Cheryl reported, disabling autolocker actually catches a 00 mode successfully for some reason. Having the autolocker enabled does not acquire a resonance, but rather kicks the servo out of resonance. We than guessed that this may be due to a loo-low oscillation threshold releasing the control loop unnecessarily, and pulled up the threshold from 1 V to 2 V. This setting acquired a resonance once for the first trial, but in the later trials, it never acquired a resonance.

The FSS autolocker needs a more thorough investigation.