M-S Cash Drawer 7193 - Manual (Page 90)

7193 Owner’s Guide Commands
May 1996
Real Time Commands
The Real Time commands correct difficulties with the original version of the 7193
RS-232C communication interface:
•
Real Time Status Transmission: GS (Hex 1D) Sequence and DLE (Hex 10)
Sequence
•
Real Time Request to Printer: GS (Hex 1D) Sequence and DLE (Hex 10)
Sequence
•
Real Time Printer Status Transmission
The original Printer Status commands, Transmit Printer Status (Hex 1B 76,
ASCII ESC v)
and Transmit Cash Drawer Status (Hex 1B 75 0, ASCII ESC u 0)
are placed in the printer’s data buffer as they are received and handled by the
firmware in the order in which they were received. If the paper exhausts while
printing data which was in the buffer ahead of the status command, the printer
goes busy at the RS-232C interface and suspends processing the data in the buffer
until paper is reloaded. This is true for all error conditions: knife home error,
thermal printhead overheat, etc. In addition, there is no way to restart the printer
after a paper jam or other error.
The Real Time commands are implemented in two ways to correct these
problems. Both implementations offer the same functionality; which one you
choose depends on the current usage of your application.
First Implementation
For a new application the GS (Hex 1D) sequences of the first implementation are
recommended to avoid possible misinterpretation of a DLE (Hex 10) sequence as
a Clear Printer (Hex 10 0, ASCII DLE NUL) command.
The first implementation builds upon the GS ENQ sequence as implemented on
Epson’s TM-930II™, TM-950™ and TM-U950™ by defining two new GS (Hex
1D) sequences to provide the same functions as the DLE (Hex 10) sequences
above, and to provide complete backward compatibility to the original 7193 Clear
Printer command.
An application using these GS (Hex 1D) sequences does not need to distinguish
for the printer between the new Real Time commands and the old Clear Printer
command. This implementation is ideal for an existing 7193 application which
already uses the Clear Printer command or for a new application being
developed.
This implementation also provides the original GS ENQ Real Time sequence in
addition to the newer Real Time sequences.