M Buttons
There are two completely different purposes for the M Buttons.
(1)Like other buttons, they can be assigned to send a command when pressed.
(2)They can serve as instant Machine
For example, in the initialized (Factory preset) state, M1 through M4 are programmed to represent MMC ID numbers 1 through 4.
Suppose M1 is lit, and the rest of the M buttons are not. The next time Play is pressed, only MIDI machines with an ID# of 1 will go into play.
Suppose M1 through M4 are lit. The next time Play is pressed, MIDI machines with ID# 1 through 4 will go into play.
This concept doesn't just apply to Play, all the Transport, Locate, and Jog / Shuttle controls will behave this way.
The M buttons are "targeting" which machines will respond.
It is as though the transport, locate, and jog / shuttle controls "look at" which M buttons are lit, so they "know" which machines to control.
The M buttons do not have to be used in this manner. As stated at the top of this page, they can be assigned like any other button, to simply send or not sent a MIDI command.
If the M buttons have not been set up to act as Machine Enable buttons, then the Transport, Locate, and Jog / Shuttle commands will be sent out to all machines, using MMC "ID All" commands.
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