Exhauster control: off in air braked condition, on in vacuum braked condition. Slave cutout. Deactivates the control jumper to a second blue star equipped loco. (Turns off working in multiple)
The exhausters are part of the vacuum braking system. If they malfunction, they can be disabled this way. In TSW, they'll never malfunction, so you can ignore this. "Slave cutout" is used in conjunction with the slow-speed system, when you are running with more than one locomotive. Unloaded wagons might be so easy to move that the power of two locomotives results in too much speed, even with the control - especially since the speed control only acts on the lead locomotive. Pressing this button removes the power of the other locomotive, allowing the lead locomotive to assume full control of speed. Note that this is something you'd use when running through an MGR loading or unloading facility, such as the one at Redcar.
Well, the master key would always be activated while you are in the middle of driving from that cab, whether in slow-speed mode or not. If you're referring to the moment you turn the key, then no. At that point all the controls are in quiescent positions, so neither locomotive is producing power anyway. It's a facility provided specifically for use while slow-speed shunting, and resets itself when the throttle is closed.
Only 1 cab is active, all non driving cabs the master key is off & the automatic brake valve in neutral / shut down.
Slave Cutout is not a switch, only a momentary-press button. It has no function in setting up the locos for working in multiple. It is only used in certain specific circumstances, usually involving the loading or unloading of wagons under slow-speed control.
