Digital Equipment RapidPrint 500, Reference Manual

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UNIX Host Setup Selecting A Printing Method
10 - 1
10 - UNIX Host Setup
This chapter covers print configuration for TCP/IP hosts.
The server must have an IP address before configuration (see your Configuration Guide for
details). Any host wishing to access the RapidPrint 500 will have to be informed of this IP address,
which is typically configured in the UNIX /etc/hosts file or via a nameserver.
NOTE: One of the most common causes of IP network problems is duplicate IP addresses.
Please make sure that your RapidPrint 500 has a unique IP address.
10.1 Selecting A Printing Method
The RapidPrint 500 provides two major TCP/IP printing methods: Berkeley remote LPR and
RTEL host software. Both methods provide queueing of jobs if the RapidPrint 500 is busy with
another job. If custom queueing software has been designed, raw TCP/IP or Telnet socket connec-
tions can be made directly to the RapidPrint 500 ports.
NOTE: See the man pages included with the distribution CD-ROM for a full discussion of
RTEL functionality and configuration.
Instructions for host configuration for LPR, RTEL, and socket connections are described in the fol-
lowing sections. Please read through the entire configuration procedure before beginning.
1. LPR
LPR allows the RapidPrint 500 to look like a UNIX host that can print files. It is
the recommended way of printing because it is easy to set up and requires no
additional host software. However, not all machines (notably machines running
UNIX based on System V instead of BSD) support the lpr system.
NOTE: The RapidPrint 500 cannot implement all lpr options; the print job information is
not available until the print job is completed.
2. RTEL Host Software
Digital supplies RTEL software, which requires installation and configuration
on the host but provides more functionality than remote-LPR. It allows the host’s
lp or lpr printing system to transparently use the RapidPrint 500 print devices,
and also allows the creation of named pipe devices on the host that map to the
RapidPrint 500’s ports.
A. The RTEL backend filter interfaces with the host-based spooling system. It
receives data from the spooling system and sends the data to the RapidPrint
500. The advantages of the backend filter are that the banner page is printed
at the front of a job, multiple copies can be printed, and simple reformatting
such as <LF> to <CR><LF> conversion and tab expansion can be per-
formed. However, the backend filter does not support any complicated out-
put filtering or conversions.
B. The RTEL Pipe Daemon process (RTELPD) uses a UNIX named pipe as its
interface to the host. This allows any host- or user-supplied backend filter
to be used for printing. Any data that is sent into the pipe is simply moved
to the RapidPrint 500. However, the data flow is one-way from the host sys-
tem to the RapidPrint 500 and this approach does require one RTELPD dae-
mon process for each print queue configured.