There are four general types of PCL5 printer commands:
These codes initiate a printer function. Control codes are composed of a single character with an ASCII decimal value of less than 32. The print server reads a control character as a command to be performed and not as data to be printed. An important control code is Escape (<ESC>, decimal value = 27, hex value = 1B) — indicating the beginning of an escape sequence. It identifies the string of characters in an escape sequence as a printer command.
These commands provide access to the PCL mode of the print server.
These commands define the print image and allow you to exit from and return to the PCL mode.
The HP Printer Job Language (PJL) offers you more control over your print jobs and provides for status feedback information.