Model USB-IIRO-16 is an ideal portable solution for adding easy-to-install isolated input and relay output digital I/O capabilities to any PC or embedded system with a USB port. Featuring 16 Form C (SPDT) electromechanical relays and 16 optically isolated digital inputs, the unit is the smallest of its kind for digital monitoring and control using USB. The isolated, non-polarized inputs may be driven by either DC sources of 3-31 V (or higher by special order) or AC sources at frequencies of 40 Hz to 10kHz. Optically isolating the digital inputs from each other, and from the computer, assures smooth, error-free data transmission in noisy, real-world environments. The input channels are available via a 34-pin IDC type vertical header. The relay outputs are de-energized at power-up to prevent an unintended control output signal. Data to the relays is latched. The relay contacts are available via a 50-pin IDC type vertical header. The rugged industrial unit contains an internal, removable screw termination board (USB-STB-84) with onboard removable screw terminals to simplify wiring connections. The USB-STB-84 mounts directly into the vertical IDC connectors of the USB-IIRO-16 PCB. The USB-IIRO-16, like the PC/104 and PCI versions, is excellent in applications where on-board relays are required and inputs must be isolated such as in test equipment, instrumentation, and process control. The USB-IIRO-16 is a USB 2.0 device, offering the highest speed available with the USB bus. It is fully compatible with both USB 1.1 and USB 2.0 ports. The OEM version provides just the board without the enclosure and internal screw termination board and is ideal for a variety of embedded OEM applications.