Programming instructions

The PRBUF Protocol is designed for downloading bitmap print image
data directly from an application program, such as a Windows printer
driver, directly to the printer’s image buffer in connection with the
PRBUF statement.
The protocol consist of a two-byte header and a number of data bytes:
Header
Byte No 1. is always the @-sign (Commercial at; Unicode 0x0040) and
indicates start of the protocol header.
Byte No 2 is:
0 Reserved (bitmap format)
1 Reserved (RLL image format)
2 RLL buffer format
3-255 Reserved
RLL Buffer format
The RLL buffer format is optimized for use by Windows drivers. In most
cases the performance of the host outruns the performance of the printer,
so it is preferred to to do most of the processing in the host before sending
the job down to the printer.
- Data byte 1 & 2 specifi es the pixelwidth (unsigned) of data in BIG
Endian format for one line.
- Data byte 3 & 4 specifi es the pixelheight (unsigned) of the buffer when
it is expanded BIG Endian.
- Data byte 5-nn specifi es the bitmap in RLL format.
Example of RLL buffer protocol header, 515x212 pixels hexdump:
40 02 02 03 00 d4
RLL format
The RLL format is good for black and white pixel runs. It compresses data
in both dimensions. It works well with one-dimensional bar codes, but
grayscales grow in size instead of shrinking. The format is symmetric
so that all pixel runs start and end with a white pixel and with line
repetitions whenever applicable. This makes the format possible to
turn upside down.
The RLL format is specifi ed on the next page.
PRBUF-Protocol
Intermec Fingerprint v7.61 – Programmer’s Reference Manual Ed. 7286
Chapter 3 Image Transfer