RCA TP-15 Multiplexer vs TP-11

[John Hafer]

Does anyone have any knowledge on the old RCA film chain mutiplexers TP-15 and TP-11 used in television broadcast stations?

What I am trying to find out is if the TP-11 had fixed mirrors to direct the projector images into the film camera, or of they were motorized like in the TP-15 which could select which projector image was directed into the film camera.

If they were fixed, then how would one select which projector was selected, or was it from simply turning on and off the projector lamp?