Today, Chandra R. had the MCE representative on site and we were able to demonstrate to him the steps that we had done during our normal operation that had resulting in CP4's bake-out controller violating our specified 1C / hour maximum rate of change.  Specifically, if the SETPOINT value is manually lowered to something less than the real-time measured temperature (TC1 supplies this) input while the program is running, and in the initial RAMP stage of the ramp/soak heating profile, the program responds by advancing to the SOAK segment of the profile.  This is logical and expected.  However, if then the SETPOINT value is raised to a value greater than the real-time measured temperature, the program does not revert back to the RAMP segment but stays in the SOAK mode.  This is a problem.  In that, the output of the controller is not limited to the 1C / hour rate of change while in the SOAK segment and is thus free to increase the heater output as high as needed to get the real-time measured temperature to match the new value of SETPOINT.  This situation happened to us and could have been damaging if left unnoticed for too long (see https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=40867).  

Anyway, the MCE guy acknowledged this shortcoming of their in-house code and resolved to develop a patch and get back to us.  In the meantime, we now know the cause, effect and workaround so have opted to continue with the in-progress bake of CP4.