Printer Interface; Graphics - Digital Equipment LG plus Series Maintenance Manual

Loss of + 48 V is seen by the RSP and reported as a fault.

Printer Interface

The printer interface is the point where the data line from the host computer
plugs into the printer. The printer interface processes all signals and data to
and from the host computer.
The printer is equipped with buffered IEEE 1284 parallel, EIA–232–D serial,
and EIA–422–A interfaces mounted on the CMX controller board. The
interface cable connectors are accessible through a cutout at the rear of the
card cage. These interfaces accept data in the U.S. ASCII protocol.
Only one of these interfaces can be used at a time, and is selected at the
control panel from the configuration menus. Only one parallel host computer
can be connected at a time.

Graphics

Two graphics programming languages that install in flash memory on the
controller board are available to the customer as optional features:
IGP/PGL Printronix Graphics Language (a Printronix IGP graphics
board emulation)
IGP/VGL Code V Graphics Language (a QMS graphics board
emulation)
These languages simplify the job of creating forms, bar codes, logos,
expanded characters, and other graphics. These options enable the printer to
print sideways, upside down, and make forms combining graphics,
alphanumeric data, and bar codes—all in a single pass. Documents
explaining configuration, operation, and programming are included with
printers that have these options.
Principles of Operation 6–19