Digital I/O module capabilities depend on the type of digital signals that the module can measure or generate and the chassis the module is used in.
Serial digital I/O modules: NI 9375, NI 9403, NI 9425, NI 9426, NI 9476, NI 9477, and NI 9478.
Parallel digital I/O modules: NI 9344, NI 9401, NI 9402, NI 9411, NI 9421, NI 9422, NI 9423, NI 9435, NI 9436, NI 9437, NI 9472, NI 9474, NI 9475, NI 9481, NI 9482, and NI 9485.
Onboard parallel digital I/O modules on sbRIO-9628 and 9638: DIO 0-3, DIO 4-11, DIO 12-19, and DIO 20-27.
The modules can perform the following tasks.
Serial and parallel modules:
Parallel modules: