Hi,
For what I have found I can infer that a “digital potentiometer” is a device which you can change the resistance depending on a digital input. This digital input can be controlled though SPI, serial, or any other type of digital communication, in the case of SPI none of the boards you have will do native SPI. You can program your card to talk to a SPI device but it will not be supported. A very good resource is this discussion forum where the customer is trying to build a SPI interface from an M-series. You can take a look at: Digital Potentiometer Discussion Forums #1 and #2.
I can see that you have email our customer support where you have selected the “digital potentiometer” attached. From page 7 of this manual, I can tell that you can control this device with either of the cards but you will need to write the code that will handle this application.
I hope it helps
Jaime Hoffiz
National Instruments
Product Expert
