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    FrankT
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Question about the MIDI Spec

Hi All,

I have a question regarding ETC's implementation of the MIDI Control Change Message Format, on the Expression 3 Lighting board.

Using the Expression 3, Ver 3.1 User manual on page 281 it says: All numbers are in Hex format. But then goes on to state:

<Bn><kk><vv>

B Control Change Status

n MIDI Channel Number (0 -F)

kk Control number (70 - 92)

vv Control Value (0 - F)

My question is the kk Control Number, is that Hex 70 (112 dec) or decimal 70 because the numbers it quotes on page 282 aren't sequential Hex characters, they're sequential decimal.

Then, Looking at the ETC_MIDI_1992_Edited manual on page 6, it contradicts this information saying the Control number is 0 - 79 and then contradicts this on the next page saying it's 70 - 79 but it too does not specify whether it's Hex or Decimal. (It looks like decimal as well).

Could you please advise what are the correct values since the actual MIDI Specification is a 7 bit Binary word ( 0x00 - 0x7fh ) or ( 0 - 127d) and will be dependent upon your implementation.

Best Regards,

Frank

 

  • Hello Frank

         For Expression 3 Ver. 3.1 the MIDI Control Change Message Format   kk Control number (70 - 92) is in fact a presented as a decimal number between 70 - 92. Once you figure out which command you want to send from page 282, you convert that number to hex.  For example with console set at Midi channel 1.  To send a macro execution for macro 1, Controller change 85  (55 in Hex) I sent B0  55  01.  I hope that clarifies the matter and sorry for the confusion.

    The discrepancy with the other manual, The  ETC_MIDI_1992_Edited is because that manual is for  Expression 1 and not for Expression 2/3.  That too is probably a decimal number that would need to be converted to Hex.

    Turk Wilson

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