fairly basic MIDI question… (trying to understand 1991 light desk manual)

Mar 22, 2008 at 2:25am

fairly basic MIDI question… (trying to understand 1991 light desk manual)

Hello forum members, I’m newly registered and am a musician/sound artist/recordist practicing round London. I’m trying to understand how to correctly format a MIDI message for a lighting controller.

I’ve got a variable voltage regulator controlling some sound synthesis, and I want it to culminate with a spasmodic dimming of the stage lights. I thought the best way to do this would be to send some messages to the Grand Master Fade.

Trouble is that I’m not getting to grips with how to compose this MIDI message, and how to wield it in max. I have researched the subject and related concepts, I just cant get my head round it.

The manual says to construct it as so:

http://img210.imageshack.us/img210/1441/snapshot20080322012232xi0.png

If someone could tell me a good way to send a fixed message to this particular controller that would be very helpful! Then I can reverse engineer it and I’ll be a happy man for my show starting next tuesday

Thanks in advance

#36460
Mar 22, 2008 at 3:57am

Walter,

It looks like the “Grand Master Fader” requires a continuous controller 13 message.

The MIDI bytes are listed there in the manual as hexadecimal (base 16) numbers.

Bn means “continuous controller number on channel n”. B is equivalent to decimal 11 in the 16s column, which would be 176 (11×16). n is the channel number on which your device is receiving (from 0 to 15, the way the computer understands it, rather than from 1 to 16 the way humans talk about it) So, for example, if your device is set to receive on MIDI channel 1, you would add 0 to 176 and get 176. (For MIDI channel 2 you would add 1 to 176 and get 177, etc.)

The next number is the continuous controller number for addressing the grand master fader. It’s hexadecimal 0D, which is equivalent to decimal 13.

The next number is anything from 0 to 127 that specifies the fader’s virtual position. Presumably 127 means fader fully up, and 0 means fader fully down.

So (assuming for the sake of this example that your device is set to receive on MIDI channel 1) to control the grand master fader, send the message “176 13 127″ to a ‘midiout’ object to turn the fader up to full. Another way to do this would be to use a ‘ctlout’ object, send the number 1 in the right inlet, the number 13 in the middle inlet, and then send 127 in the left inlet.

To create a continuous fade, send successive messages with gradually changing fader position values.

For most of the other faders, it looks like you need to send *two* continuous controller messages to set a fader position. So, for example, to control the “A Crossfader”, first send it “Bn 0C 10″ (hexadecimal), which is to say “176 12 16″ (decimal), then send it “Bn 10 vv” which is to say “176 16 127″ (or whatever fader value you desire). Get it?

Here’s a little patch that demonstrates. Hope it helps. (Double-click on the midiout or ctlout object and make sure that it’s addressing the correct device, then set the correct MIDI channel, then move the fader.)

Best,

Chris

—–

max v2;
#N vpatcher 10 59 685 470;
#P window setfont “Fixedwidth Serif” 18.;
#P window linecount 1;
#P newex 443 277 109 1441810 pack 0 13;
#P newex 443 311 142 1441810 midiformat 1;
#P newex 443 339 87 1441810 midiout;
#P number 443 252 48 18 0 127 3 22 0 0 0 221 221 221 222 222 222 0 0 0;
#P window setfont Times 18.;
#P window linecount 2;
#P comment 566 248 60 1310738 MIDI channel;
#P window setfont “Fixedwidth Serif” 18.;
#P number 575 286 35 18 1 16 3 22 0 0 0 221 221 221 222 222 222 0 0 0;
#P user uslider 443 104 18 128 128 1 0 0;
#P window setfont Times 18.;
#P window linecount 3;
#P comment 427 48 60 1310738 Grand Master Fader;
#P window linecount 1;
#P comment 313 224 35 1310738 OR;
#P window setfont “Fixedwidth Serif” 18.;
#P number 62 254 48 18 0 127 3 22 0 0 0 221 221 221 222 222 222 0 0 0;
#P newex 62 279 131 1441810 ctlout 13 1;
#P window setfont Times 18.;
#P window linecount 2;
#P comment 173 216 60 1310738 MIDI channel;
#P window setfont “Fixedwidth Serif” 18.;
#P number 182 254 35 18 1 16 3 22 0 0 0 221 221 221 222 222 222 0 0 0;
#P user uslider 62 106 18 128 128 1 0 0;
#P window setfont Times 18.;
#P window linecount 3;
#P comment 46 50 60 1310738 Grand Master Fader;
#P connect 1 0 5 0;
#P connect 5 0 4 0;
#P connect 2 0 4 2;
#P connect 8 0 11 0;
#P connect 11 0 14 0;
#P connect 13 0 12 0;
#P fasten 14 0 13 2 448 306 492 306;
#P connect 9 0 13 6;
#P pop;

#125163
Mar 23, 2008 at 11:45pm

thanks so much for your help man – now you have given me the answer I see what a buffoon like question is was, your patience is appreciated. I was in the theatre space today having some fun!

#125164

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