Table of Contents
Advertisement
Printers
Printers in a 3708 network environment operating in protocol conversion mode can
provide a printed copy of information that is displayed at a terminal, or they can be
used to print data from a host application program. Printed data appears in the
same alphanumeric characters and symbols that appear on a display, and printouts
can be formatted the same way a display is formatted.
The printers can be bound by the host applications to operate using either LV type 1
SCS protocol or LV type 3 DSC protocols, described earlier in this chapter.
The ASCII printers attached to a 3708 port in protocol conversion mode appear to
the host as 3287 printers. The 3708 sends ASCII data and ASCII control characters,
as described in the LV type 1 and LV type 3 data stream sections, that cause the
host data to print on the ASCII device as it would on a 3287. In addition, plotters
may be attached in this mode, and the LV type 1 transparency command can be
used to cause graphic data to be transmitted to the plotter.
In order for a printer to be attached in this mode, it must have the following
characteristics:
• Full duplex communication at speeds from 110 bps to 19.2 Kbps
• A serial interface (EIA 232C)
• ANSI 128-character set support (7-bit ASCII characters with or without parity)
• 256-character set support with the LV type 1 SCS data stream
• XON and XOFF pacing using only the DCI and DC3 ASCII codes
• The printer must support the following ASCII control characters:
X' OD' -- CR -- Carriage Return
-
X'OA' -- LF -- Line Feed
-
X '7F' -- DEL -- Delete (the printer must ignore these characters)
• The printer must not perform a LF when a CR is received
• The printer must not perform a CR when a LF is received
• The printer must not require any special ASCII sequences to be sent to it for
initialization.
Configuring a Printer for Protocol Conversion Mode
In order for a printer to operate in protocol conversion mode, the 3708 port must be
configured with DEVICE TYPE
=
3 (printer). It cannot be configured as a
keyboard with printer, even though the device may, in fact, have a keyboard. (When
the DEVICE TYPE is set to indicate a keyboard with printer, the 3708 assumes that
it is operating in protocol enveloping mode.) A keyboard with printer configured for
use as a printer will have output only capabilities, except for the following 3287
functions supported by the 3708:
Hold Print
Enable Print,
Cancel Print,
PAl, and
PA2.
Note: The printer of a keyboard display-with-printer device may also be defined so
that it is accessible for host data and local copies. See "Displays with Printers" on
page 4-89 for information on this type of device.
Chapter 4. Protocol Conversion Mode
4 .. 79
Advertisement
Table of Contents
