PJL can use alphanumeric variables, numeric variabless and strings.
1.4.1. Alphanumeric variables
The first character must always be a character in the allowable range of letters and digits. Letters consists
of the uppercase characters (ASCII 65-90) and lowercase characters (ASCII 97-122). Digits consists of
the numbers 0-9 (ASCII 48-57).
1.4.2. Numeric variables
The number consists of digits with one optional decimal point and an optional + or - sign preceding the
Strings consist of any combination of characters from ASCII 32 to 255, plus ASCII 9, except ASCII 34
(quotation marks), which are used to define the start and end of a string.
"Print Job KKK"
"This is a sample string"
There are two general types of invalid commands. Each type operates differently.
Syntax errors include :
unrecognized command and command modifier
strings which are missing quotation marks
numeric values which are missing digits before the decimal point
1.5.1. Syntax errors
Commands received with Syntax errors cause the printer to ignore the entire PJL command.
1.5.2. Syntax warning and semantic warning
Syntax warnings and semantic warnings are issued for commands which include unsupported options, values
which are out of range, or wrong or missing commands, etc. When the printer receives commands which
would create a syntax warning or semantic warning, it operates the command as long as possible, however,
the portion of the command which would create a warning is ignored.
CHAPTER 5 PJL - 7