If you use the SCXI-1127 as a traditional DAQ device, you can only select certain topologies. We have this note in the Help file, under Device Overview>>NI SCXI-1127:
If you configure the SCXI-1127/1128 as a Traditional NI-DAQ Device, you can only select the 2-wire 32x1 multiplexer, 2-wire 4x8 matrix, and independent topologies. To use the SCXI-1127/1128 as 1-wire, 2-wire, and 4-wire multiplexer, select the 2-wire 32x1 multiplexer topology and configure all channels appropriately in MAX.