----- Original Message -----
From: "Pete Turnbull" <pete_at_dunnington.u-net.com>
To: <classiccmp_at_classiccmp.org>
Sent: Sunday, February 10, 2002 07:39 AM
Subject: Re: 10Base-FL
>
> 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.
HALF
> 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
Received on Sun Feb 10 2002 - 07:46:15 GMT