10 Feb
2002
10 Feb
'02
7:46 a.m.
----- Original Message -----
From: "Pete Turnbull" <pete(a)dunnington.u-net.com>
To: <classiccmp(a)classiccmp.org>
Sent: Sunday, February 10, 2002 07:39 AM
Subject: Re: 10Base-FL
HALF
It ought to work, with Rx on one connected by fibre to Tx on the other,
and
v.v.
That was what I thought too.
> Ok. They have a three-positon DIP switch, labeled `SQE TEST',
`ALTERNATE
COLL MODE'
and `FULL STEP'. Does that narrow it down?
SQE TEST is the "heartbeat" function, or Signal Quality Enable setting,
which is normally off if connecting the AUI to any kind of repeater,
otherwise on. Try it both ways.
ALTERNATE COLL MODE is to do with collision detect timing. On 3Com units
(and they bought ORnet/Chipcom) turning it on is the default, and arranges
that a single collision-presence (CI) signal is sent to the AUI interface.
If off, CI is active all the time the collision condition persists, which
is the normal setting for IEEE 802.3 compliance (the 3Com setting is an
optimisation for certain interface chips).
FULL STEP is to do with the signal sent at the beginning of a packet. STEP is normally used for 802.3 Ethernet, FULL STEP is
used for DIX
Ethernet. It won't hurt to try both ways.
Ok. When I first got 'em, I tried 'em out real quick, just to see if they
worked. IIRC I did flip the collision mode switch, but I didn't go through
all the permutations. I'll try that next time I get a chance.
Another possibility is that you have the wrong type of AUI cable (old ones
use different shielding arrangements, and most "office" type cables are
way
below spec) or even the wrong kind of AUI interface
for this device.
I didn't know about that. Are AUI cables easily made, or are they better
purchased? I need a small handful to connect my VAXen to the DELNI anyway.
I have two of the DEC mfgr'd 10Km^H^H^H^H20m cables, and two or three that
came with the DELNI that I expected to work. Another assumption on my part
I should look into.
Still another is that your fibre is too lossy, and the transceiver is
seeing something, but not recognising it (there's a continuous series of
pulses at 1MHz rate when it's active). Try cleaning the ends with
iso-propyl alcohol, and swap the sides over. Blow out the connectors with
dry compressed air and/or IPA.
The fiber was a 2 meter patch panel that I open especially for the job, it
should be ok. The tranceivers now... I did pull the piece of styrefoam(sp)
outta the ST connector, but I didn't blow 'em out. There's a can of air
laying around at the office, I'll borrow it Monday. It _is_ seeing
something, as I do get a link light on the hub, and the error on the
tranceiver goes from no-signal to invalid-data when I plug in the fiber.
What is the ORnet transceiver connected to?
Uhhh... $PC for testing, I believe. Some NE2k clone card most likely. It
was a quick go-nogo test.
--
Pete Peter Turnbull
Bob