The ADLINK PXI 7931 is a matrix module with 32 cross-point 2-wire relays. This provides greater flexibility than a multiplexer because any input can be connected to any output individually or in combination, and so you can connect the source or measurement module to multiple test units at the same time. Also if you want to change the connection path, simply reconfigure the matrix without having to change the wiring
The default configuration is 4 groups of 2x4 2-wire matrix, which can be changed to 2 groups of 2x8 or 4x4, or 1 group of 4x8 or 2x16. The contact position of relays can be changed either by software commands, or previously stored scan list.