USB 6501 digital I/O device includes 24 digital I/O lines and a 32-bit counter. Because of its small size, plug-and-play connectivity and portability, the USB is practical for a wide range of users, from students and technicians to engineers and scientists. Engineers can use the 24 digital I/O lines to interface with LEDs, switches, relays and other digital I/O devices. Each digital I/O signal is protected against overvoltage, undervoltage and overcurrent conditions. The device includes a 32-bit counter and has built-in, removable screw terminals, eliminating the need for additional connectivity accessories. For embedded OEM applications, a board-only design with a 36-pin ribbon cable header instead of screw terminals is available.