This 30-inch USB to RS485 adapter cable turns your computer's USB port into an RS422 or RS485 serial port and avoids the expense of upgrading your reliable serial devices. No external power source is needed. Just connect the cable to your computer and insert the included CD into your computer's CD drive in order to launch the driver and assign the cable a COM port. It supports USB 2.0 specifications and data transfer speeds up to 230 Kbps, which is almost twice as fast as a built-in serial port. It is backward compatible with USB 1.1 devices.The hot-swappable USB to RS422 adapter with built-in FTDI chipset offers COM retention. It automatically reassigns the same COM port values to each port, so when the cable is disconnected or the system is rebooted, no additional configuration is needed. The FTDI USB to serial adapter also supports RS485 auto-transceiver turn around with unique featured ATTA hardware, as well as remote wake-up and power management. A DB9-to-terminal-block adapter is included for making hardwire connections.Foil and braid shielding helps fight against electromagnetic interference and radio frequency interference (EMI/RFI) that impedes your signal and can distort or destroy data. The auto-sensing feature solves DCE/DTE conflicts without the need for cross-wired serial cables or adapters. The U209-30N-IND is backed by a 3-year warranty, ensuring reliability and performance.