TransAct Ithaca 280, Руководство программиста

Страница: 182 / 318

Programming Codes iTherm
®
280 Programmer’s Guide
Page 170 Rev K
IEEE 1284 Mode Inquire
In parallel, IEEE 1284 mode, status information can be returned to the host through the
IEEE 1284 reverse channel. After the host makes an inquire request, it activates IEEE
1284 mode 0 reverse channel and waits for a response from the printer. The response to
the inquire is identical to serial mode in format.
The printer always accepts IEEE 1284 reverse-channel requests but does not accept
inquire commands when off-line. It is possible to obtain status when off-line by placing
the printer in dynamic response mode before the printer goes off-line. The IEEE 1284
reverse channel responds to status changes even when the printer is off-line.
In general,
the printer should be configured for ―Buffer Full Only‖ off-line operation if
inquire commands are used. This prevents the printer from using flow control for
anything but buffer full. The programmer must take on the responsibility for assuring that
inquire commands are used to maintain status of the printer.
Inquire Commands
[ENQ] Inquire printer status
ASCII [ENQ] <n>
Hexadecimal 05H <n>
Decimal <5> <n>
IPCL none
EPOS [GS] r or [DLE] [ENQ] or [DLE] [EOT]
Description
The [ENQ] <n> command inquires about the printer‘s status and returns a
result.
Note: When the printer is off-line, inquires may not be accepted.
[ENQ] <1> Inquire Cash Drawer 1 status
ASCII [ENQ] <1>
Hexadecimal 05H 01H
Decimal <5> <1>
Function Cash Drawer 1 Status
Response ACK <1> (06H 01H) Cash Drawer 1 is closed.
NAK <1> (15H 01H) Cash Drawer 1 is open.
Cash drawer status is defined as open circuit being drawer closed.
[ENQ] <3> Inquire receipt paper low status
ASCII [ENQ] <3>
Hexadecimal 05H 03H
Decimal <5> <3>
Function Receipt paper low
Response ACK <3> (06H 03H) Receipt paper is present.
NAK <3> (15H 03H) Receipt paper is low.