Chapter 4: Communication
Communication Overview
A program translates the data from the host computer to a language the printer can
understand. This program must be in place so that the printer can print a receipt. It
must tell the printer exactly how to print each character. This chapter describes how to
create a program or modify an existing one.
Interface
Set up a communication link so that the printer can communicate with the host. The
7169 model supports the industry standard USB communication interface. This interface
has a protocol associated with it that the host computer must understand and adhere.
The printer also supports RS–232C communications.
The host and printer can communicate only when the interface parameters are matched
and the proper protocol is used. The 7169 ethernet model supports the ethernet
communication interface.
Sending commands
After the communication link is established, commands can be sent to the printer. This
section describes how to send commands to the printer using DOS and BASIC.
Note: This section does not take into account the necessary protocol, but is meant as a
general introduction to how the printer functions.
Using BASIC to send commands
In BASIC, printer commands are sent as a string of characters preceded with the
LPRINT command.
Example: LPRINT CHR$(&H0A)
This command sends the hexadecimal number 0A to the printer. With the command,
the printer prints the contents of its print buffer. Previously sent commands tell the
printer exactly how the data should be printed on the paper.
Example: LPRINT CHR$(&H12); "ABC"; CHR$(&H0A)
This command sends the Hex numbers 12 41 42 43 0A to the printer. With the
command, the printer then sets itself to double wide mode (12), loads the print buffer
with “ABC” (41 42 43), and finally, prints (0A). The communication link that the
BASIC program uses for the output must be matched with that of the printer’s.
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