Hi Airton
Adam is correct here. To add a bit more detail, the 64 outputs on the MADI card will still be available to you once you have moved it to the xDR-16 Port B, but 8 of these outputs will be shared with the 8 output sockets on the xDR. The software allows you to choose where this overlap is, so in your case where you would like to record 32 channels, you could set the xDR-16 output sockets to overlap with MADI channels 33-40, which you would not be using.
As for inputs from the card, you will be able to use the first 16 inputs from the MADI card when it is moved to the xDR-16.
Cheers
– Jeff, A&H