Check the listing for details. national instruments NI-9401. Condition: Used. Listed at 178.00 USD. national instruments NI-9401. This is for a used NI-9401 module. This has not been tested but worked well in my lab setup. Fine details listed below 👇 5 V/TTL, 8 Bidirectional Channels, 100 ns C Series Digital Module—The NI‑9401 is a configurable digital I/O interface for input or output in 4‑bit increments. Therefore, the NI‑9401 can create three configurations: 8 digital inputs, 8 digital outputs, or four digital inputs and four digital outputs. With reconfigurable I/O (RIO) technology (CompactRIO only), you can use the LabVIEW FPGA Module to program the NI‑9401 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. Thank you for your interest in this item! Please note: Returns are not accepted. Buyer is responsible for inspecting shipping box for damage and reporting it to the shipping provider. I will add additional foam protection to the device to help ensure a safe delivery to your location. Any return will be at the purchasers expense and will not be guaranteed a refund