TransAct Epic 3000, Руководство программиста

Страница: 78 / 271

Programming Codes T480 Programmer’s Guide
Page
78
Rev A 100-14362
254 for difference compression
255 for same as previous scan line data
<data> = the data bytes that define the graphics to be printed.
[ESC] * Set horizontal graphic mode
ASCII [ESC] * <m> <0> <0>
Hexadecimal 1BH 2AH <m> <0> <0>
Decimal <27> <42> <m> <0> <0>
IPCL none
Description The [ESC] * <m> <0> <0> command selects one of the three graphic
modes specified by <m>. The two bytes after the mode must be zero.
Where <m>
0,2,3,4,5,6,7 Standard Graphic Modes (See ESC * command
documentation in previous section.)
8,9 Not supported
10 102 x 102dpi 1 horizontal, 1 vertical pass
11 203 x 102 dpi 2 horizontal, 1 vertical pass
12 102 x 203 dpi 1 horizontal, 2 vertical passes
13 203 x 203 dpi 2 horizontal, 2 vertical passes
14,15,16 Not supported
Note 1: Only modes 10 thorough 13 should be selected for horizontal
graphics.
Example Command Comment
[ESC] * <10> <0> <0> Set resolution to 100x96 dpi.
[ESC] h <1> <9> <0> <eight data bytes> Send 8-bytes red pixels.
[ESC] h <2> <9> <0> <eight data bytes> Send 8-bytes green pixels.
[ESC] h <3> <9> <0> <eight data bytes> Send 8-bytes blue pixels.
LF Send line feed to force print of any buffered data not yet printed.
Note 2: Graphic data is committed to paper when more than 12 dot rows
have been transmitted to the printer. If less than 12 dot rows have been
sent, they are not printed until the line is terminated (i.e. a line feed
command is sent). To make graphics faster to send and smaller to store,
several algorithms are included with the graphic command to compress
the data.
Graphics Compression
Although the printer compression algorithms are documented, it is recommended that
our Windows’ printer driver be used to generate a graphic image. Our Windows’ printer
driver selects the best compression method to use on a scan line by scan line basis.
The print driver can be directed to print to file, creating a .prn file. When creating a .prn
file, it is recommended that the Start/End Doc settings be cleared in the Start/End Doc
tab of the printer properties page. After the .prn file is created, it can be read and sent to
the printer by the host application.
Bit wise RLE. In bit wise RLE compression, the Most Significant Bit (MSB) compression
of each data byte denotes if the compressed data represents one or zero bits. Bits zero