Great for linking older serial devices to computers or laptops with USB ports. Offers 2-wire RS-485 or 4-wire RS-422/RS-485 operation. Holds connections tight with its high-retention USB connector. USB 1.0, USB 1.1, and USB 2.0 compatible (12 Mbps). Interface powered. No external power required. Serial terminal block can be removed for easy wiring. LEDs indicate transmitting and receiving of data. This compact device quickly converts USB port connections to RS-422/485 so you can connect legacy serial devices to a newer PC or laptop. Continue to use legacy commercial and industrial RS-422/485 devices without making any changes to the applications written for them. Plus, because it features 2000-volt optical isolation, you can protect your PC and other equipment from dangerous spikes and surges on the RS-485/RS-422 network. Simply plug it into your PC's USB port using the included USB cable (3-ft.), then configure its DIP switches for 2- or 4-wire operation. The converter will show up as an additional COM port in your PC's Windows Device Manager.