CPX = Command-Post Exercise. It's a form of "skeleton" training
with basic equipment & only minimum personnel, usually
conducted during all combat vocational courses & also without
the main body at the unit itself. Can take place within camp
environs (eg. parade square or auditorium) or in real outfield.
Usually only day-long, so that can sent back stores by book-out
time.
Dunno what TCS means, though one online reference alludes to it as
"signaller + driver." Guess it means the typical commander or
trainer/controller Land Rover, lah. Both "zay chia" (sit vehicle),
except one is tactical while the other can roll up canopy & the
driver/signaller sleep a lot (i.e. whenever not on the move).
"Bns" was the quoter's short-form for BN (battalion).