HP 800 Syntax of Escape Sequences, Two-Character Escape Sequences, Parameterized Escape Sequences

Introduction to HP PCL

Once an HP PCL command sets a parameter, that parameter will remain set until that HP PCL command is repeated with a new value, the printer is reset to its user default environment, or another command makes a change. For example, if you send the printer a command to set line spacing to 3 lines/inch, each page will print 3 lines/inch until the printer receives a Line Spacing or VMI command or the printer is reset.

5.2Syntax of Escape Sequences

There are two forms of HP PCL escape sequences: two-character escape sequences and parameterized escape sequences.

5.2.1Two-Character Escape Sequences

Two-character escape sequences have the following form: Esc X

Where "X" is a character that defines the operation to be performed. (Note, "X" may be any character from the ASCII table within the range 48-126 decimal ["0" through "~"]).

Following are examples of two- character escape sequences:

Esc E a two-character escape sequence used for resetting the printer.

Esc 9 a two-character escape sequence used for resetting the left and right margins.

5.2.2Parameterized Escape Sequences

Parameterized escape sequences have the following form: Esc X y # z1 # z2 # z3 … # Zn[data]

Where y, #, zi (z1, z2, z3… ) and [data] may be optional, depending on the command.

X Parameterized Character - A character from the ASCII table within the range 33-47 deci- mal ("!" through "/") indicating that the escape sequence is parameterized.

y Group Character - A character from the ASCII table within the range 96-126 decimal (" ' " through "~") which specifies the group type of control being performed.

# Value Field - A group of characters specifying a numeric value. The numeric value is rep- resented as an ASCII string of characters within the range 48-57 decimal ("0" through "9") that may be preceded by a + or - sign and may contain a fractional portion indicated by the digits after a decimal point (.). Numeric value fields are within the range -32767 to 32767. If an escape sequence requires a value field and a value is not specified, a value of zero is assumed.

14 HP DeskJet 600, 700, 800, 900 & HP 2000 Series PCL Developer’s Guide