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.