Check the listing for details. National Instruments NI 9402 cDAQ Digital Input / Output Module. Condition: Used. Listed at 245.00 USD. National Instruments 9402 digital I/O module. Tested, fully functional, and in excellent physical condition. Note that digital lines on this device are LVTTL, 3.3V level. LVTTL, 4 Bidirectional Channels, 55 ns C Series Digital Module—The NI‑9402 is a per‑channel configurable digital I/O interface for input or output. With reconfigurable I/O (RIO) technology (CompactRIO only), you can use the LabVIEW FPGA Module to program the NI‑9402 for implementing custom, high-speed counter/timers; digital communication protocols; pulse generation; and more. Each channel features transient isolation between the I/O channels and the backplane. For additional information and resources, use the model name to search the manufacturer's website.