Universal Serial Bus (USB) has become the connectivity workhorse of today’s PCs, replacing the familiar serial ports. However, many commercial and industrial devices still use the RS-485 interface. To connect these devices to modern PCs, you need a simple and reliable conversion solution. The 485USBTB-2W-LS offers RS-485 2-wire conversion in a space saving, USB port-powered package. Simply plug the converter in and Windows will install the FTDI Virtual COM (VCP) driver software. The USB converter will appear in Windows Device Manager as an additional COM port. A one meter USB cable is included.Locked Serial Numbers Explained - The "locked serial number" format uses the same serial number (same COM port) that is associated with a given model type. If the converter is shared among several computers, like field service laptops, a locked serial number model lets you plug and play without having to worry about matching the two.