Printronix P5000LJ Series - Manual (Page 23)

Graphics Options
23
Graphics Options
The PGL and VGL emulations allow you to create and store forms; generate
logos, bar codes, and expanded characters; and create other graphics.
Alphanumerics and bar code data are added as the form is printed.
Protocols And Emulations
A protocol is a set of rules governing the exchange of information between the
printer and its host computer. These rules consist of codes which manipulate
and print data and allow for machine-to-machine communication. A printer
and its host computer must use the same protocol.
Most impact printers use single ASCII character codes to print text, numbers,
and punctuation marks. Some characters, both singularly and in groups of two
or more, are defined as control codes. Control codes instruct the printer to
perform specific functions, such as underlining text, printing subscripts,
setting page margins, etc. The main difference between most printer
protocols is in the characters used to create control codes and the ways in
which these characters are formatted.
When the printer executes the character and control codes of a particular
printer protocol, it is “emulating” that printer. For example, if the printer uses
the Proprinter III XL protocol, it is emulating an IBM Proprinter III XL printer; if
the printer is using the Epson FX-1050 printer protocol, it is in Epson FX-1050
emulation mode. As used in this manual, “protocol” and “emulation” mean the
same thing.