The NCE USB interface board provides a means of connecting a computer to the NCE cab bus. While primarily designed to provide a computer interface to the Power Cab program track, it can additionally be used with any NCE system to run trains, control signals, turnouts and Program on the Main (OPs mode programming). When used with the Power Cab the USB board cab bus address must be 3. When the appropriate shunts are installed to configure the USB board for use with a Power Cab the address is automatically forced to cab bus address 3. When configured for a different NCE system the cab bus address can be changed via a command (binary command 0xB1) through the USB port. Optoisolated USB prevents “sneak path” short circuits when connected to a computer. You may use as many USB interface boards as you wish, up to the limit of available cab addresses on your DCC system.