Revision D 12/09 | Chapter 3: Programming the Printer | 23 |
Chapter 3: Programming the Printer
Overview of commands
Commands control all operations and functions of the printer. This includes selecting the size and placement of characters and graphics on the receipt to feeding and cutting the paper. The programming commands have been organized, in order of hexadecimal code within functional groups. For this reason, “related” commands may not be listed adjacent to one another.
The operation of various printers may be emulated by the commands, including the following:
•A793
•A794
•LEGACY
Any of the commands may be used in any combination to program a host computer to communicate with the printer (unless otherwise noted).
Some commands listed and described here may not be implemented and are identified as “not implemented.” If received, they are ignored and not sent to the print buffer as data.
Any nonlegal commands have their parameter sent to the print buffer as data.
Comparison to A793
The following table details the list of commands whose behavior differs between the A793, A794, and A799 because of the physical differences of a 6 dots/mm head (A793) versus an 8 dots/mm head (A794 and A799).
Command | Description | Difference between previous product | |
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| and new product emulation mode. |
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15 n | Feed n dot rows | This command will move the paper on the receipt in | |
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| n/203 inch steps instead of n/152 inch steps. |
16 n | Add n extra dot rows | The dot rows will be measured in n/203 inches versus | |
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| n/152 inches. |
1B | 20 n | Set | This command sets the right side spacing to “n” horizontal |
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| motion units. By default, these units are in terms of 1/203 |
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| inches versus 1/152 inches. |
1B | 24 n1 n2 | Set absolute starting position | For graphics commands, the position is scaled to best |
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| match A793. In text mode, the equivalent character |
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| position is calculated. |
1B | 26 s c1 c2 n1 d1...nn dn] | Define | Since the dots on the A799 printhead are smaller, user |
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| defined characters that were used on the previous printers |
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| will appear smaller on the A799 printer. |
1B | 2A m n1 n2 d1...dn | Select bit image mode | In A793 emulation mode, graphics are scaled to best |
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| match the size of the graphic in the A793 printer. |
1B | 33 n | Set line spacing | This command uses n in terms of n/360 inches. Since the |
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| A793 had a fundamental step of 1/152 inch and the A799 |
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| has a fundamental step of 1/203 inch, the actual line |
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| spacing will not exactly match the requested spacing. |
Continued...
