| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 339.1 | | KONING::KONING | Brivu Latviju! | Mon Sep 16 1991 16:13 | 11 |
| I don't think it's documented in any world-readable document.
The simple answer is "the same way that your telephone at home carries
two-way voice communication over a single wire pair". Basically the
receiver circuit measures the voltage on the wire, then subtracts out
what's put there by the transmitter, and what's left is the received signal.
Incidentally, the terminal to keyboard connection on the VT100 works the
same way...
paul
|
| 339.2 | Can this be industry standard? | OSAV20::IZUTANI | Kenji Izutani,Tech.Consul.,CSEC,DEC-Japan | Mon Sep 16 1991 20:27 | 9 |
| To confirm the reply....
Does it mean that a baseband signaling with amplititude (of DC voltage)
discriminator is used for two-way communication on a ThinWire?
I wonder if this technology will be "ANSI" standardized?
regards,
kenji
|
| 339.3 | | KONING::KONING | Brivu Latviju! | Tue Sep 17 1991 11:06 | 8 |
| Yes, it's baseband signalling. I'm not sure what you mean by "discriminator"
or whether that's a good way to describe it.
It doesn't appear that this will be pushed as an ANSI standard, though
technically speaking it could be. The major ANSI interest is in twisted
pair cables.
paul
|
| 339.4 | generic RG58U cabel could be used? | OSAV20::IZUTANI | Kenji Izutani,Tech.Consul.,CSEC,DEC-Japan | Tue Sep 17 1991 20:12 | 8 |
| "discriminator" means that receiver circuit of ThinWire PMD can see the
difference of DC voltages of its sending signal and receiving signal.
Is there a tester for this signaling for field personel use? I guess there is
some RG58U type cable that is not our ThinWire at the customer site and
anxious about how to certify them.
kenji
|
| 339.5 | | KONING::KONING | Brivu Latviju! | Wed Sep 18 1991 13:42 | 17 |
| I asked about test procedures and got this answer:
From: LEVERS::J_FITZGERALD "John Fitzgerald 227-3646" Date: 18-Sep-91 12:36 PM
To: KONING::KONING
cc: WORDY::CDAY,J_FITZGERALD
Subject: RE: Thinwire test/cert procedure?
Paul, Yes we do have a procedure that gives a quick check of the
cable. Understand, we only recommend thinwire, as "RG58" means many
different specs. to different vendors. The test procedure does use a TDR
and specifies a return loss maximum. This procedure is part of the
DEFCN-TA and DEFZA-CA installation guides. I believe Cynthia Day,
who I have CC'ed on this note, can supply a pointer to this document..
Thanks,
John
|
| 339.6 | Thank you! | OSAV20::IZUTANI | Kenji Izutani,Tech.Consul.,CSEC,DEC-Japan | Wed Sep 18 1991 19:54 | 0
|