The USB-4761 is a relay actuator and isolated D/I module for USB bus. It provides 8 optically-isolated digital inputs with isolation protection of 2,500VDC for collecting digital inputs in noisy environments and 8 relay actuators for serving as on/off control devices or small power switches. For easy monitoring, each relay is equipped with one red LED to show its on/off status. The USB-4761's 8 optically-isolated digital input channels are ideal for digital input in noisy environments or with floating potentials.