U disk is the role of uploading programs
U disk is USB Flash drive,an external flash drive, small enough to carry on a key ring, that can be used with any computer that has a USB port.
Now led sign use U disk to upload the program,Note that it is “upload”, not “store”.
Program of sign is edited on the computer, then transport program into the sign with U disk,U disk is a transport tool . After U disk is inserted ,sign read it, meantime display “Updating…” on LED panel.When reading finish,Sign display new program from U disk,At this time, please remove U disk.