Saf plasmatome netrajet 120HPBurny3.5

Hello Every one

I have CNC Plasma model Saf with netrajet 3.5 burny
the Machine is operate but cant load file from serial device like pc or RS232 how i can use PC for download program on cnc machine
When i select the third option from main menu (Load) the second screen is have four option the fourth option is serial device but when i select it the third screen just showing list which is empty program not show the load from option like floppy or burny how i can show list of serial device.

Please help us