M Buttons - JLCooper Electronics MCS-3800 User's Reference Manual

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 Enable-Disable buttons.
They control which machine will respond to Transport, Locate,
and Jog / Shuttle commands.
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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