M-S Cash Drawer 7193 manual Alternate Implementation, Rules for Using Real Time Commands

Commands 7193 Owner’s Guide

Alternate Implementation

The alternate implementation uses the DLE (Hex 10) sequences as implemented on Epson’s TM-T85™ and TM-U950™. An application using these DLE (Hex 10) sequences and the original 7193 Clear Printer command must distinguish for the printer between the new Real Time commands and the old Clear Printer command by adding a NUL (Hex 00) to the Clear Printer command.

An application using these DLE (Hex 10) sequences must also send the second byte of the sequence within 100 milliseconds of the first, to prevent the first byte being mistaken for a Clear Printer command. This implementation is useful for an existing TM-T85™ or TM-U950™ application which is being migrated to a 7193. This application would not be using the 7193 Clear Printer command at all since it is not recognized by the Epson printers.

Note: The DLE (Hex 10) sequences as implemented on Epson’s TM-T85™ and TM-U950™ are not exactly the same as those implemented on Epson’s TM-950™.

This implementation also provides the original GS ENQ Real Time sequence in addition to the newer Real Time sequences.

Rules for Using Real Time Commands

Three situations must be understood when using Real Time commands.

1.First, the printer executes the Real Time command upon receiving it and will transmit status regardless of the condition of the DSR signal.

2.Second, the printer transmits status whenever it receives the Real Time status transmission command sequence, even if that sequence happens to occur within the data of another command, such as graphics data.

In this case the sequence will also be handled correctly as the graphics data it is intended to be, when the graphics command is executed from the buffer.

3.Care must be taken not to send a Real Time command within the data sequence of another command that consists of two or more bytes.

In this case the printer will use the Real Time command sequence bytes instead of the other command’s bytes when finally executing that other command from the buffer or the other command will not be executed correctly.

These three situations generally preclude use of standard DOS drivers for the serial communication ports when using Real Time commands.

88 May 1996