From my research on options for SPDIF, along with other Digital Audio interfaces, the best option includes NI AudioMASTER with NI PXI/PCI 781xR/783xR hardware. Here is a pretty comprehensive overview regarding NI AudioMASTER for Analog and Digital Audio.
I am not sure the speeds of the SPDIF signal you will be testing, but if you could get the SPDIF signal to a BNC cable it is feasible, with post-processing, that the signal could be measured with a counter or HSDIO card. I also want to warn you that this is not documented in any KnowledgeBase article or resource I was able to find.
The PCI-7813R and the NI CB-2180 look like a good pair, but is it required that I purchase the AudioMaster software? It would appear that the CB-2180 is only $1200 and the PCI-7813R is $2500, yet the audio master suite is $10k. I dont really need any of the audio analysis software, I only need to ability to get SPDIF data into labview.
It looks as though I cannot purchase the CB-2180 on its own. As an alternative I could purchase a PCI-7813R and provide my own electrical interface, but in that case would I need the FPGA add on for labview to compile the SPDIF example code for it?
Yes, I believe you would need to use the LabVIEW FPGA Module in order to program the NI PCI-7813R. At least that is what I deduce from the NI PCI-7813R product page. It may be worthwhile double-checking this information in the LabVIEW FPGA forum.
Laurine, there is currently no native NI solution for SPDIF outside of the option mentioned above. It is possible to build your own using other NI high speed digital hardware. Alternatively, for some SPDIF tests, using an SPDIF to analog converter along with a analog board like the the 4461 or 4463 is sufficient.