How to serve multiple AS/400's with PSF/6000 to print
ITEM: RTA000099225
Q:
ABSTRACT: How to serve multiple AS/400's with PSF/6000 to print
on a 3900-001.
SEARCH ARG: psf/6000 external hard|disk
TOPIC THREAD: PRINT
PSF/AIX
..
Customer has fewer than 10 AS/400's and one MVS host. She has one
3900-001 printer attached to MVS. She wants to install PSF/6000 to act
as a print server for all hosts above. She said she will use a two
channel switch on the 3900. One channel for MVS and the other for the
PSF/6000 which is serving the AS/400's.
We know the two channel switch is manual. Assume we have the channel
enabled for the PSF/6000 traffic. How can all of her AS/400s feed the
PSF/6000 server? I see that PSF/Direct is supported on OS/400. With
this I would think only one AS/400 would be talking through the PSF/6000
server at a time. It appears that no DPF capabilities exist.
With this, do I have to establish a time-out for each AS/400, to let
each AS/400 have a turn to print? Is there another way to share the
3900-001 when using PSF/6000? Please advise. Thanksą
A:
You're correct -- there is no DPF function in PSF/AIX. For connectivity
from the AS/400 to PSF/AIX printers, you can use either PSF Direct (SNA)
or TCP/IP with remote writers (starting in OS/400 V3.1). The latter is
the closest we have to DPF, and I would recommend it over PSF Direct
for sharing one printer between that many hosts. There are differences
between the solutions, particularly when it comes to operator control
(with PSF Direct, operator control is through the host spool; with
TCP/IP, the jobs are placed on the AIX spool and operator control is
through AIX) and protocol (PSF Direct is SNA; remote writer is TCP/IP)
so the final solution will depend on customer preference.
1) PSF Direct can be used to connect multiple hosts to a single server,
and in the AIX implementation, there is no hard limit to the number of
connections. Only one host can be active at a time, e.g., only one
PSF/400 can be printing at a time as you noted. While one AS/400 is
printing, one or more AS/400s or host PSFs or PSF/AIX may be trying
to make a connection. As soon as the currently printing AS/400 closes
the connection to PSF Direct, one of the other PSFs can then connect
to PSF Direct.
The best explanation for setting the timers on PSF/400 and PSF/6000
for such an arrangement are in APAR SA44303 (note that PTF SF24143
for OS/400 V3R1 is required).
2) OS/400 V3R1 introduced Remote System Printing and remote output
queues. This provides support in OS/400 for automatically routing a
spooled file to a printer connected to another system, including
PSF/AIX. Please see Chapter 4 of the AS/400 Printer Device Programming
manual. It has a complete description of how to set up a Remote Writer
in OS/400 V3.
This is somewhat similar to DPF in that jobs are spooled to the AIX
system from each AS/400 as the jobs are ready and then managed by the
AIX spooling subsystem. It's different than DPF in that the datastream
sent to AIX is not IPDS; only *AFPDS, *USERASCII, and *SCS are
supported. Resources are not sent with the job and must be available
on the RS/6000 at print processing time.
I think the latter would be a better solution for your customer
because with TCP/IP and LPD, multiple hosts can simultaneously route
output to the AIX spooling subsystem; the qdaemon will then manage the
printing of jobs from the various AS/400s. PSF/AIX maintains the
two-way IPDS conversation with the printer so resources stay loaded
in the printer (according to the tuning parameters in PSF/AIX). You
could support the AS/400s using TCP/IP, and support the MVS host either
through the two-channel switch (as you described), or through PSF Direct
(SNA) with the 3900 channel-attached to the RS/6000, or via TCP/IP from
MVS with the Download feature of PSF/MVS--several choices, the latter
two of which would eliminate the need for the two-channel switch on the
3900 and the manual switching your customer currently plans.
With PSF Direct, you are dependent on timers for the different AS/400s
to have access to the 3900. Each time you start a new PSF Direct
session, all resources must be reloaded to printer memory, so there
will be some overhead for initialization at each changeover.
I hope this helps.
S e a r c h - k e y w o r d s:
CROSS PSF/6000 PSF/AIX AS/400 OS/400 DIRECT TCP/IP REMOTE SHARE
WWQA: ITEM: RTA000099225 ITEM: RTA000099225
Dated: 06/1998 Category: XPSF6000
This HTML file was generated 99/06/24~12:43:33
Comments or suggestions?
Contact us