Commands
See Also
ESC *
Expression
ASCII ESC @
Decimal 2764
Hex 1B40
Parameters
None
ETB Raster Mode Compressed Graphics
Description
Provided for LabelWriter print er raster compatibility.
The ETB command is a syn chronization charact er used to encode compressed raster
bitmap print data. Print data is encoded in strin gs of8-bi t bytes preceded by a singe
ETB (Hex 17) character. The control electronics in t he printer do not check the v alidity
of the bitmap da ta.
Data compression is do ne through a formof run -length encodin g. Bit seven (the sign
bit) of a compressed character represents the value to be printed:
0 = white space, 1 = a printed pixel. Bits 6 th rough 0 represent the number of
consecutive bit s of the selected v alue plus 1.
Examples:
00 = 1 white pix el
80 = 1 printed pixel
0F = 16 whit e pixels
FF= 128 printed pixels
The data sent to the LabelW riter printer is handled on a line-by -line basis, so
compressed lines may be in termixed with normal li nes. In addition, th e compressed
mode also uses the set bytes per line command (ESC D) to determine h ow much data
fromt he host to expect for each line. How ever,t he sum of the pixels must be equal to
the bytes per line variable (ESC D, default o n the LabelWriter SE450 printer is 56)
multiplied by 8. No error checking is don eo n the incoming data and unexp ected results
will occur if th is caution is not observed.
Below is a sample compressed line for a ESC D 24 setting :
17 OF 8F 20 A0 20 A0 0F 8F
which would transl ate to:
16 white pixels
16 printed pixels
32 white pixels
32 printed pixels
32 white pixels
31