Re: [LAD] [semi-OT] midi snakes using CAT5?

From: Raymond Martin <laseray@email-addr-hidden>
Date: Sun Nov 01 2009 - 20:11:45 EET

On November 1, 2009 12:55:44 pm you wrote:
> On Sun, 2009-11-01 at 12:56 -0400, Raymond Martin wrote:
> > 15 meters is a recommendation based on typical cables used in a simple
> > system. Data corruption ensues somewhere after 15m, depending on cable
> > quality, EMI, and so forth. I would imagine a CAT5 as having better
> > shielding and IIRC runs for that are advised to somewhere up to 50m.
> > Different frequency ranges though, so signal loss/degradation per meter
> > may vary.
>
> My recollection is that when MIDI was originally standardised, they
> needed to specify a maximum length, and that 15M was chosen somewhat
> arbitrarily (No tests were done, no eye patterns examined).
>
> Now midi is actually at heart a 5mA current loop interface running at a
> fairly low baud rate (31.25 Kbaud IIRC), so should be good for far more
> then 15m without any problem, however nobody really knows and it will
> depend a bit on the environment and the receiver.
>
> Interference is unlikely to be an issue assuming good quality twisted
> pair cable (Cat 5 counts), but bulk capacitance just might ultimately
> limit the length.
>

Check MIDI manufacturers association pages, specifically:
http://www.midi.org/aboutmidi/tut_midicables.php

At the bottom it talks abut MIDI over Ethernet, with links.

Cheers,

Raymond
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Received on Sun Nov 1 20:15:06 2009

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