5 V/TTL, 32 Bidirectional Channels, 7 µs C Series Digital Module. The NI-9403 is a configurable digital I/O interface for input or output with shift-on-the-fly capabilities. Each channel features transient isolation between the I/O channels and the backplane. With reconfigurable I/O (RIO) technology (CompactRIO only), you can use the LabVIEW FPGA Module to program the NI-9403 for applications such as custom, high-speed counter/timers, digital communication protocols, and pulse generation. In a CompactDAQ chassis, you can use the NI-9403 only as a static (software-timed) digital I/O module. You cannot use these modules to route timing or triggering signals.