TX7332: opening the TR switch

If I have two TX7332 connected to an AFE, and I want to switch the one TX off (open the T/R switches), I would use the  TR_SW_DIS_xx
What power mode must I be in to disable the signal from going through the unused (with disabled TR_SW_DIS_xx) TX7332.
hopefully the TX7332 can be off (global power down).... but would that make no sense, as I have to set up that register (and I guess power is required to open the T/R switch) .
Possibly there is a sequence I must use, which can keep the unused TX7332 in low power which still opening the T/R switch (disabling the switch).
we are only using on-chip beamforming (so that you can reduce the scope of your reply)

We have 3 power modes (for pulse echo):
1) Global power down: is the T/R switch open, closed, or based on TR_SW_DIS_xx?
2) Default Power Mode
2) Dynamic power mode ?  : 
3) Transmit-less Power Mode ?

Then we have Pulser Power Down: PDN_PUL_n   then makes T/R switch active....what does this mean? That it is open. closed, or controllable depending on the power mode?