Technical data

6.2.1.3 Setting Printer Connection Level
Some printers use more features that a connection offers than do others. For
example, some printers provide status messages on a serial back channel
while others do not. To provide support for a broad range of connection types,
the print system uses the
printer-connection-level attribute. The
recognized values are 0 through 5, as listed in Table 6–2.
Table 6–2: Printer Connection Level Values
Value Description
0
None specified. Use system default.
1
Output-only data (unidirectional). Printers that are unidirectional
only cannot report conditions such as paper-out, jammed, or off-line
to the supervisor process. The supervisor relies on flow control
(if that is available) to prevent the flow of document data when
the printer is powered down or unavailable.
2
Output-only data; status bits returned. Printers that report
status in the form of status bits can supply the supervisor
with some status information, such as when the printer is
offline or when an engine error occurs.
3
Bidirectional, without synchronized session control. PostScript
printers that exploit a bidirectional data connection send a wide
variety of more detailed printer status messages to the host. The print
system supervisor converts many such printer messages to events
and problem text, which is available for display by clients.
4
Bidirectional, with synchronized session control. See note
on PostScript printers for value 3.
5
DIGITAL PrintServer.
The printer attribute files provided with the print system software contain
an appropriate connection level definition for each supported printer.
Under normal circumstances, you should not need to change the value of
the printer-connection-level attribute from its printer attribute file
setting, because the printer and its interconnect typically define the level.
However, use of terminal servers or other special purpose interfaces affect
the level of support that the print system can provide and might require that
you lower the connection level to get reliable, though less capable, support
for a printer.
6.2.1.4 Setting Serial Port Parameter Attributes
Connecting a printer to a serial port requires that you specify several
communications parameters. If you do not specify the attribute
printer-baud-rate, the print system assumes that you have correctly
Creating and Managing Queues and Printers 6–7