Chapter 5: Pcl5 Emulation: Lexmark; New Pcl5 Commands To Support Bar Codes; Bar Code Descriptor Esc&X#W[Descriptor Data]; Transfer Bar Code Data Esc&Y#W[Bar Code Data] - Lexmark T656 Technical Reference Manual

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PCL5 emulation: Lexmark
This section discusses the Lexmark-specific commands implemented in the Forms and Bar Code
Card. The HP-specific section is found immediately preceding this section.

New PCL5 commands to support bar codes

Support of new bar code functionality (for example, two-dimensional symbology PDF417) requires
new Lexmark-unique PCL5 definitions that provide access to the new functionality. Two new
ESC ESC
commands are implemented, &x#W and
&y#W.
ESC
Bar code descriptor &x#W[descriptor data]
This new escape sequence is used to describe not only what bar code to print, but all of the
parameter settings required to build the bar code. The first two bytes of this command designate the
symbology. The remaining bytes are then interpreted accordingly, based on the symbology. Each
symbology has its own defined descriptor header. The first two bytes are required. The remaining
bytes are optional. If those bytes are not sent, the settings are set to appropriate defaults. The
number of bytes of descriptor data is indicated by #.
ESC
Transfer bar code data &y#W[bar code data]
This new PCL5 command is used to transfer a raw block of bar code data to be encoded. The bar
code data is encoded according to what was specified in the last valid bar code descriptor command
received. If no valid descriptor is sent, then this command is ignored and the data is flushed. The
number of bytes of descriptor data is indicated by #.

Compatibility safeguard

These two new commands, if sent to an HP printer, are flushed and nothing prints. There is a
possibility that a future HP PCL5 enhancement could utilize the two escape sequences that have
been chosen, forcing future Forms and Bar Code Card PCL5 emulations to honor the HP versions of
these commands and to ignore them in a bar code context. To avoid this conflict, use the PCL5
Lexmark enhancement switch. Setting or not setting this switch would let a future Forms and Bar
Code Card PCL5 emulation decide which way to interpret the new escape sequences. The switch is
a GL/2 command:
PCL5 emulation: Lexmark
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