Hello,
The LFH160 has twisted pairs. I am not an expert in the Ethernet protocol, but I guess as long as the signals are within the specifications of the card, it should be fine.
http://www.ni.com/documentation/en/pxi-multiplexer-switch-module/latest/specs-pxi-2576/specs/
Mind the bandwidth and mind the minimum switch load. Not meeting the minimum will decrease the switch device's life.
https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z0000019LKTSA2
Switches with Reed, SSR or FET relays don't have this problem. The PXI-2530B is Reed, has a >12 MHz bandwidth and it has the same 2-wire 64x1, 2-wire dual 32x1 and 2-wire quad 16x1 topologies as the PXI-2576. It is a bit more costly, but I thought you may be interested. The 2530B version of the LFH160 cable is not twisted pair, though, so maybe in this case, a front mount Terminal Block with external twisted pairs may be a better option.
Hope it helps. Please let us know if you have further question.
Regards,
Camilo V.
National Instruments
