I/O Expansion Unit with 8 Slots and 1x USB Port. USB-87Pn is an unit to expand I/O via the USB. It is designed to be used in harsh and noisy environment, so the hardware is manufactured with wide power input range (10 ~ 30 VDC), isolated power input and can operate under wide temperature (-25 ~ +75°C). To simplify installation and maintenance of I/O modules, it provides many useful features, such as: hot swap allowed, auto configuration, LED indi..