kyle.ryan@LIGO.ORG - posted 07:43, Sunday 11 March 2018 - last comment - 02:39, Monday 12 March 2018(40950)
CP4 bake-out controller in "HOLD" again
Output has been at 100& for days now so this won't impact anything. If situation were different, i.e. were weren't already at 100% output but still ramping up, then this "bug" could have resulted in an over temperature condition. The program is behaving as if the "HOLD" condition is a function of run time based on 1C / hour expected rate of rise and time needed to get to SETPOINT value from measured temperature recorded at start of profile. If so, then this is a novice programmer mistake. The program should switch to the HOLD segment upon reaching the SETPOINT value as a function of the measured temperature irregardless of time so as to always be limited to the 1C / hour maximum rate of rise.
I also witnessed this happen on Friday when the control sensor clearly hadn't reached the set point yet and program transitioned to hold at temp. Heater had been at 100% output overnight.
Temperature at GV11 in air for the past 3 days.