HP Pcl 5 Manual

							ENSyntax of Escape Sequences 1-5
Syntax of Escape Sequences 
There are two forms of PCL escape sequences: two-character 
escape sequences and parameterized escape sequences.
Two-Character Escape Sequences
Two-character escape sequences have the following form:
? X
where “X” is a character that defines the operation to be performed. 
“X” may be any character from the ASCII table within the range 
48-126 decimal (“0” through “~” - see Appendix A). For a list of the 
two-character escape sequences supported by the printer, refer to the 
“PCL Feature Support Matrix” in Chapter 1 of the PCL 5 Comparison 
Guide.
Following are examples of two-character escape sequences:
? Ea two-character escape sequence used for 
resetting the printer. 
? 9a two-character escape sequence used for 
resetting the left and right margins to the printer’s 
default settings.  
						

							1-6   Introduction to HP PCLEN
Parameterized Escape Sequences
Parameterized escape sequences have the following form:
?  X  y  z1  #  z2  #  z3  ...  #  Zn[data]
where y,  #, zi (z1, z2, z3...) and [data] may be optional, depending on 
the command.
XParameterized Character - A character from the 
ASCII table within the range 33-47 decimal 
(“!” through “/”) indicating that the escape sequence is 
parameterized.
yGroup Character - A character from the ASCII table 
within the range 96-126 decimal (“ ‘ ” through “ ~ ”) that 
specifies the group type of control being performed.
# Value Field - A group of characters specifying a 
numeric value. The numeric value is represented 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 
65535. If an escape sequence requires a value field 
and a value is not specified, a value of zero is 
assumed.
ziParameter Character - Any character from the ASCII 
table within the range 96-126 decimal (“ ‘ ” through 
“ ~ ”). This character specifies the parameter to which 
the previous value field applies. This character is used 
when combining escape sequences.
ZnTermination Character - Any character from the 
ASCII table within the range 64-94 decimal 
(“ @ ” through “ ^ ”). This character specifies the 
parameter to which the previous value field applies. 
This character terminates the escape sequence.
[data]Binary Data is eight-bit data (for example, graphics 
data, downloaded fonts, etc.). The number of bytes of 
binary data is specified by the value field of the escape 
sequence. Binary data immediately follows the 
terminating character of the escape sequence.  
						

							ENSyntax of Escape Sequences 1-7 The following is an example of an escape sequence with a 
termination character and no parameter character. This escape 
sequence performs a single function.
NotesSome escape sequences shown in this manual contain spaces 
between characters for clarity. Do not include these spaces when 
using escape sequences.
Also, in the escape sequence a script “
l” is used to indicate a lower 
case “l” for clarity. 
The following is an example of an escape sequence with a parameter 
character and a termination character. This escape sequence 
performs two functions. It is the combination of two commands 
(?&l1O and ?&l2A):
Notice that the “?”and the “&l”are dropped from the second printer 
command when the two commands are combined. Also, the 
upper-case “O” that terminated the first command becomes a 
lower-case “o” parameter character when these commands are 
combined. 
						

							1-8   Introduction to HP PCLEN
Use these three rules to combine and shorten printer commands:
1The first two characters after “?” (the parameterized and group 
character) must be the same in all of the commands to be 
combined. In the example above, these are “
&” and “l”.
2All alphabetic characters within the combined printer command 
are lower-case, except the final letter which is always upper-case. 
In the combined example above, “O” becomes “o”. The final 
character in the printer command must always be upper-case to 
let the printer know that the command is complete.
3The printer commands are performed in the order that they are 
combined (from left to right). Be sure to combine commands in 
the order that they are to be performed.  
						

							ENIntroduction 2-1
2
The Page 
Introduction
This chapter describes the PCL coordinate system. It defines 
the logical page and the printable area; it introduces the HP-GL/2 
(vector graphics) picture frame, and identifies the boundaries of each. 
						

							2-2   The PageEN
Logical Page 
The PCL logical page (also referred to as the PCL addressable area) 
defines the area in which the PCL cursor can be positioned. Although 
the printer does not actually have a cursor (like the blinking underline 
character used on most computer terminals), the cursor position 
refers to the Currently Active Position of the cursor (also referred to as 
the CAP). The location of the “cursor” is the position on the logical 
page where the next character will be positioned. The cursor can be 
moved to different points on the logical page using the cursor 
positioning commands (see Chapter 6, Cursor Positioning). The PCL 
cursor cannot be moved outside of the logical page bounds.
The size of the logical page for the media (paper, transparencies, 
labels, etc.) is defined in Table 2-1 and Table 2-2. 
						

							ENPrinted Dots 2-3
Printed Dots 
The high quality output achieved by HP LaserJet printers is due in 
part to the ability to lay down a fine grid of “dots” on the page. The 
density of this grid is referred to as the printer’s resolution. From  
the first HP LaserJet (the “LaserJet Classic”) until recently, all 
HP LaserJet family printers printed at a resolution of 300 
dots-per-inch. In a one inch square, the printer could print a dot 
anywhere in a grid of up to 300 dots horizontally by 300 dots 
vertically, for a total of 90,000 possible dot locations per square inch 
(300 × 300 = 90,000).
The LaserJet 4 printer is capable of printing at either 300 or 600 dpi 
resolution. At 600 dots-per-inch, it becomes possible to print up to 
360,000 dots per square inch (600 x 600 = 360,000). Print resolution 
of LaserJet 4 is selectable and can be specified either from the 
printer’s control panel or programmed through PJL commands.
Figure 2-1 300 vs 600 DPI Dot Sizes
NoteRefer to Appendix E of the PCL 5 Comparison Guide or the printer 
User’s Manual to determine the default print resolution for a specific 
HP LaserJet printer.
The printer’s physical dot size has no direct bearing on the size of 
“PCL Units” used in cursor movements. PCL Units were previously 
referred to as “PCL dots”, but should not be confused with the 
printer’s physically printed dots. The size of PCL Units can also 
be specified (see the Unit of Measure Command in Chapter 4 for 
more information). 
						

							2-4   The PageEN
PCL Coordinate System 
The PCL coordinate system is defined as shown in Figure 2-2. 
Figure 2-2 X,Y PCL Coordinates 
The point (0,0) is at the intersection of the left edge of the logical page 
and the current top margin position. 
NoteSince the point (0,0) is always at the intersection of the left edge of 
the logical page and the current top margin position, it moves if the 
top margin is changed, and rotates around the page if the orientation 
is changed.  
						

							ENUnits of the PCL Coordinate System 2-5
Units of the PCL Coordinate System 
The units of the X-axis of the PCL coordinate system may be PCL 
Units, decipoints, or columns. The units of the Y-axis may be PCL 
Units, decipoints, or rows.
PCL Units 
These are user-definable units of measure which are used in PCL 
commands affecting various PCL cursor moves. The number of 
units-per-inch used in PCL cursor moves is determined by the current 
setting of the Unit of Measure command (see “Unit of Measure 
Command” in Chapter 4).
NotePCL Units were formerly referred to as “PCL Dots”. They were 
renamed “PCL Units” to prevent confusion with the printer’s physically 
printed “dots”, which are determined by the printer’s resolution.
Decipoints 
In PCL terminology, a decipoint is 1/720 inch or one-tenth of a 
PCL point (a PCL point is 1/72 inch as opposed to a typographic point 
which is 1/72 inch).
Columns & Rows 
The width of a column is defined by the current horizontal motion 
index (HMI). The distance between rows is defined by the current 
vertical motion index (VMI), or lines-per-inch (lpi). HMI, VMI and 
lpi are described in Chapter 5, Page Control Commands.
Printer Internal Units 
Internally, the printer uses a different unit of measure. It maps PCL 
Units, decipoints, and columns and rows to this unit of measure. This 
internal unit is 1/7200 inch. All positioning is kept in internal units and 
rounded to physical dot positions when data is printed. 
						

							2-6   The PageEN
HP-GL/2 Picture Frame 
In addition to text and raster graphics, HP-GL/2 vector graphics 
can be placed on the PCL logical page. HP-GL/2 vector graphics 
are incorporated using the concept of the HP-GL/2 picture frame 
(see Figure 2-3). Within this picture frame, HP-GL/2 uses its own 
coordinate system and units of measure. The HP-GL/2 coordinate 
system and units are described in detail in Chapter 17, An 
Introduction to HP-GL/2 Vector Graphics, and Chapter 18, The 
Picture Frame.
NoteIf no HP-GL/2 picture frame size is specified (using the commands 
described in Chapter 18), then the default HP-GL/2 picture frame is 
used. The default HP-GL/2 picture frame is the current top and 
bottom margins and the left and right edges of the logical page. The 
HP-GL/2 picture frame rotates with the PCL page orientation, but is 
not affected by the PCL print direction. 
Figure 2-3 PCL Logical Page with HP-GL/2 Picture Frame