Serial cables for SAM4s registers are used for cash register to PC communications. Please keep in mind most modern PC's or lap tops no longer have a serial port (RS232) but most SAM4s registers do have a serial port.
The USB to Serial Port Adapter allows you to connect your computer's USB port to the serial port of the SAM4s cash register. Please note Software still required, Serial Cable still required. Price does not include software, Serial Cable, or Support.