I am not sure about this question, since the data sheet of NI 8221 and PXI-8220 only said that they are compatible with PXI 8171, 8170 and so on.
I have a instrument with PXI-8106 inside, and I want to check whether I can use NI 8221 or PXI-8220 to add a PCMCIA card for more functions.
I will appreciate the reply very much!