32 Line Matrix Printer PCL II Programmer's Reference Manual

Character Overstrike

To create special symbols and underline selected portions of your output, one

character (maximum) may be printed over another on a character-by-

character or line-by-line basis.

A character overstrike is accomplished using either the backspace control

code or a carriage return with no line feed. The overstrike print line will be held

in the print buffer and will be merged with the next line to form a single printed

line with superimposed characters.

Attempting to print more than two characters in any one print location will

result in a loss of data integrity. (Only the last two characters received will be

retained.)

When the automatic underlining enhancement is used (ESC&dD), the

underlined character is not considered an overstrike character. Therefore, if

the underlining enhancement was used to underline a character, another

character could still be printed over it without risking data loss.

Bar Codes

To print bar codes, escape sequences are sent to the printer specifying the

type of code, bar code height, bar code header information, placement

information, and bar code data. The following five escape sequences are

used for bar code printing:

ESC*z#V Bar Code Selection

This sequence selects the type of bar code to be used in subsequent printing

of bar code data. If a number other than those available is selected, the

previously selected bar code type will be used. The following table lists the

bar code types available and their corresponding value field numbers.

Table 10. Bar Code Types

Bar Code Type Character Length Value Field No.

Code 3 of 9 (default) Variable 0

Industrial 2 of 5 Variable 1

Interleaved 2 of 5 Variable 4

UPC A Fixed 8

UPC E Fixed 9

EAN 8 Fixed 10

EAN 13 Fixed 11

UCC/EAN-128 Fixed 12

Postnet Fixed 13, 14

Royal Mail Variable 15, 16