Forums > MaxMSP

Remote midi >100' (midi or serial over ethernet?)

September 11, 2007 | 2:45 am

Hi All,

I may have answered my own question, but maybe someone has a good HARDWARE solution to this, no laptop hanging out on stage. I have 2 midi ports on stage that needs to get to front of house on a touring show, which means potentially 100-200′ cable run. Currently it runs through a terribly unstable Midi Line Driver (mld10). I was thinking of translating the midi to tcp and feeding 10/100 ethernet down two XLR’s. I’ve only found one box that does this (kiss-box.com). Was wondering if anyone has run midi->serial->ethernet and what devices they used, and how the tcp packets were read, or did you actually find an os x driver? Any thoughts would be helpful. The key problems are portability, ease of integration (xlr is already run in every theater), stability, and cost. The kiss box is perfect, but would be $750. ethernet based serial boxes seem to only be a hundred bucks. Any comments welcome, thanks!

Brian


September 11, 2007 | 6:38 am

>Hi All,
>
>I may have answered my own question, but maybe someone has a good
>HARDWARE solution to this, no laptop hanging out on stage. I have 2
>midi ports on stage that needs to get to front of house on a touring
>show, which means potentially 100-200′ cable run. Currently it runs
>through a terribly unstable Midi Line Driver (mld10). I was
>thinking of translating the midi to tcp and feeding 10/100 ethernet
>down two XLR’s. I’ve only found one box that does this
>(kiss-box.com). Was wondering if anyone has run
>midi->serial->ethernet and what devices they used, and how the tcp
>packets were read, or did you actually find an os x driver? Any
>thoughts would be helpful. The key problems are portability, ease
>of integration (xlr is already run in every theater), stability, and
>cost. The kiss box is perfect, but would be $750. ethernet based
>serial boxes seem to only be a hundred bucks. Any comments welcome,
>thanks!

you of course know you have wireless midi now??
but i also had ok results with (home made) midi-xlr adapters, and
running long xlrs

best

kasper

Kasper T. Toeplitz
noise, composition, bass, computer

http://www.sleazeArt.com

http://www.myspace.com/sleazeart


September 11, 2007 | 12:56 pm

yes, however I don’t think I can trust any wireless device to this task. There would be no excuse for any dropped packets, and there’s no predicting what kind of space I would walk into as far as line of sight and rf noise. Maybe it performs much better than I give credit for, do you know any touring shows that use such a system? I may be convinced by first hand experience…

For your adaptor, do you just mean a passive wiring adaptor?! to run 200′? I figured was so far past the rated distance it would never work.

Thanks much,

Brian


September 13, 2007 | 7:13 am

Brian Mohr schrieb:
> Currently it runs through a terribly unstable Midi Line Driver
> (mld10).

I had never a problem with just a passive cable adapter Midi-XLR. I ran
it over 50 meters without problem, do it all the time. This is dead
cheap and works though the specs of Midi tell you it should not run more
than 15 meters. In the end Midi is very low speed, no problem for any
Midi output to drive an optocoupler 50 meters away…

The Midi Line Driver was a smart marketing idea, and is an example how
theoretical engineering (faith in specs) is sometimes not the best
solution…

Just give it a try…

Stefan


Stefan Tiedje————x——-
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September 13, 2007 | 3:08 pm

will do, thanks for the thoughts and feedback…


September 15, 2007 | 1:23 am

Quote: Stefan Tiedje wrote on Thu, 13 September 2007 01:13
—————————————————-

> In the end Midi is very low speed, no problem for any
> Midi output to drive an optocoupler 50 meters away…
>

Can you elaborate on this? I’ve used line drivers and long bare cables runs both with different digrees of success. Interested in your "drive an optocoupler" comment … thanks


September 17, 2007 | 3:40 am

Joel Walsh schrieb:
>> In the end Midi is very low speed, no problem for any Midi output
>> to drive an optocoupler 50 meters away…
>>
>
> Can you elaborate on this? I’ve used line drivers and long bare
> cables runs both with different digrees of success. Interested in
> your "drive an optocoupler" comment … thanks

Well its just an experience, a simple cable does it…
I always soldered them myself and never had a problem. I have no
experience whatsoever with line drivers, there was never a need to try
something needlessly expensive…
My "drive an optocoupler" comment is just the knowledge how the Midi
spec explains how to construct a Midi input electronically…
To run 32 kbit/s through a good cable is frequenzy wise not much
different than running audio through it. Characteristic wave impedance
of cables is important for ethernet, starting at 10 mbit/s (the very
slow one) but not so much for a bit more than audio range frequencies,
with 32 kbit/s the influence of the cabel on the overall impedance is
minimal… (Unless the distance is kilometers rather than meters… ;-)

Stefan


Stefan Tiedje————x——-
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– _|_)—-|—–()————–
———-()——–www.ccmix.com


September 19, 2007 | 12:21 pm

Hi,

I am currently in the same situation, where i would need to take a midi signal over lets say about 50 meters. I am willing to try out the self-soldering method, but i am more like a software man. Therefor could anyone give me any pointers on where to start? Actually a nice how to would even be a lot better…

thanks for the time!


September 19, 2007 | 9:09 pm

Go to fullcompass.com and buy 1 Neutrik NC3MX, 1 Neutrik NC3FX, and 2 Neutrik NYS322. Get a couple feet of ProCo raw midi cable, or microphone cable for permanent install. The reason this works is that Midi only uses 3 of the 5 pins on a 5 pin din. When looking on end at the male din connector, put the pins at the top. The pin numbers from left to right are 3, 5, 2, 4, 1. If you do the same for a male xlr, the pins are 2, 3, 1. Wire din 5 to xlr 3 with black, din 4 to xlr 2 with red or white, and din 2 to xlr 1 with ground. This maintains the ground wire and twisted pair specification. When soldering the female xlr, remember that the orientation has switched for pins 1 and 2 (as you look at the face, pin 1 is now on the left). connect your two adaptors together and run a continuity test on the 3 center pins. You should be good to go…

As for my situation, it looks like the office is springing for the Kiss box. So long as the os x driver isn’t crap, I’ll be happy as a clam. So I get to make a 10/100 over 2 xlr adaptor…


September 19, 2007 | 9:13 pm

to clarify red or white wire, if you are using midi cable, it should be white, which is the twisted pair for black. Microphone cable comes with either colors for the hot.


September 23, 2007 | 5:28 pm

Brian Mohr schrieb:
> to clarify red or white wire, if you are using midi cable, it should
> be white, which is the twisted pair for black. Microphone cable
> comes with either colors for the hot.

I usually just take a normal readymade Midi cable and cut it into half.
then solder the male XLR’s to one half and the female to the other.
(I’d never trust the colors, would always measure the connections.)
Connect pin 1 of the XLR (the shield) to the middle pin of the Midi
plug, and pins 2 and 3 to the two inner pins of the Midi plug. The outer
Midi pins are not in use…
I am pretty sure the polarity isn’t crucial, there is no problem if its
switched, but to keep the polarity of the overall cable should be easy
as well…

Stefan


Stefan Tiedje————x——-
–_____———–|————–
–(_|_ —-|—–|—–()——-
– _|_)—-|—–()————–
———-()——–www.ccmix.com


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