NCR 5972 用户手册
Chapter 4:
Programming Set Up
Firmware and software function descriptions for the NCR 5972 Retail
Display are presented in this chapter.
Display are presented in this chapter.
Host/Retail Display Command Interface
The Retail Display accepts two types of data: display data and
command data. If a byte received from the host is any character except
the ESC (0x1B) character, it is processed as a character and displayed
on the Retail Display. If an ESC character (0x1B) is received, the
subsequent byte(s) is processed as a command. If the subsequent byte
is an invalid command it is ignored. If an ESC is received, but no
command byte is received immediately, the firmware waits forever if
need be and uses the next received byte(s) to complete the command.
command data. If a byte received from the host is any character except
the ESC (0x1B) character, it is processed as a character and displayed
on the Retail Display. If an ESC character (0x1B) is received, the
subsequent byte(s) is processed as a command. If the subsequent byte
is an invalid command it is ignored. If an ESC is received, but no
command byte is received immediately, the firmware waits forever if
need be and uses the next received byte(s) to complete the command.
Note:
Each command consists of at least two bytes. The first byte
(0x1B) is a command identifier indicating the next byte(s) is a
command byte. The command byte may be followed by parameter
or data bytes depending on the command. Also note that the ESC
character can be displayed by using the Display ESC Character
command.
command byte. The command byte may be followed by parameter
or data bytes depending on the command. Also note that the ESC
character can be displayed by using the Display ESC Character
command.