Axiohm 7156 Especificações descarregar pdf (Página 118)

Commands 7156 Owner’s Guide

October 1995110

An application using these DLE 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 7156.

This application would not be using the 7156 Clear Printer command at all since

it is not recognized by the Epson printers.

Note: The DLE sequences as implemented on Epson’s TM-T85™ and TM-U950™

are not exactly the same as those implemented on Epson’s TM-950™.

Both implementations also provide the original GS ENQ real time sequence in

addition to the newer real time sequences.

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 bufferthe 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.

Another consideration is that an application should take care not to let the buffer

fill up with real time commands when the printer is busy at the RS-232C

interface. A busy condition at the RS-232C interface can be determined by bit 3 of

the response to GS ENQ or GS EOT 1 or DLE EOT 1. The reason for a

particular busy condition can be determined by other responses to GS EOT n or

DLE EOT n.

1 2 ... 113 114 115 116 117 118 119 120 121 122 123 ... 189 190

Sem comentários

Axiohm 7156 Especificações Página 118