Raster Graphics
Raster Graphics
Graphics are sent to the printer using the following escape sequences:
ESC*t[70, 140]R | Raster graphics resolution |
ESC*r#L | Horizontal raster graphics resolution |
ESC*r#V | Vertical raster graphics resolution |
The ESC*r#L and ESC*r#V escape sequences allow you to set the horizontal and vertical raster graphics resolutions independently. Valid raster graphics resolutions are 70 DPI by 72 DPI, 140 DPI by 72 DPI, 70 DPI by 144 DPI, and 140 DPI by 144 DPI. The following table lists the graphics resolution and the corresponding escape sequence used to select that graphics resolution. There are many different valid ways to select a given graphics resolution. The following table lists only one of the many valid ways.
The ESC*t#R escape sequence allows you to select a graphics resolution of either 70 x 72 dots per inch (default) or 140 x 144 dots per inch (high resolution). For example, to specify
Table 9. Graphics Resolution
Horizontal DPI | Vertical DPI | Escape Sequence |
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70 | 72 | ESC*r70l72V |
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140 | 72 | ESC*r140l72V |
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70 | 144 | ESC*r70l144V |
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140 | 144 | ESC*r140l144V |
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ESC*rA | Prepare for raster graphics (PCL Level I) |
ESC*b[# of bytes] W[binary data] | Raster data transfer (PCL Level I) |
ESC*b[# of raster lines]Y | Move paper # number of raster lines |
ESC*rB | Raster graphics complete (PCL Level I) |
The ESC*rA sequence informs the printer that a raster graphics dump is to follow the sequence. If the printer has received a partial line of ASCII data before this sequence is received, this escape sequence causes the ASCII data to be printed and a carriage return and line feed to be performed.
The ESC*b#W[binary data] sequence actually sends the raster data to the printer. This escape sequence must be sent for each raster line to be printed. The # of bytes parameter is the decimal number of bytes of binary graphics data to be sent to the printer. The binary data consists of a 1 for every dot to be printed and a 0 for every blank space.
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