Keysight technologies digital usb io modules keysight technologies u2121a the keysight technologies u2121a is an insulated digital usb io module which provides 16 inputs and 16 outputs it offers quick and easy set up with plug and play full speed usb 20 connectivity so avoiding the hassle of opening up your computer chassis this data logger has high voltage protection of 1500v eff and is therefore ideal for industrial automation and control keysight technologies u2121a digital usb io m