MMC
MMC
• MMC is part of the Universal Real-Time
System Exclusive protocol.
• Various SysEx messages have been
implemented to take advantage of MMC.
•Commands and Responses
MIDI MACHINE CONTROL
MMC
MIDI Machine Control (MMC)
was designed so that a MIDI
system could remotely control
hardware that is usually used for
recording and playing back audio
and/or video.
MIDI MACHINE CONTROL
MMC
MIDI MACHINE CONTROL MMC
A sequencer program can start,
stop, fast forward, etc. a tape
deck, video deck, or other
hardware device.
You don’t have to physically
reach over to the hardware.
MIDI MACHINE CONTROL MMC
https://www.youtube.com/watch?v=I-WoL7LzeRE
Every device that is MMC
compatible has a unique ID number
(1-128).
Each MMC device (tape deck, video
deck, drum machine, etc) should be
assigned to its own ID number so
that each device can be individually
controlled.
The sequencer can also have an ID
so that a tape deck can control the
record/playback of the sequencer.
A computer is not required to
incorporate MMC.
id:
1
A multiple modular
recorder setup (multiple
DA38s, Adats, etc.) also
may make use of MMC to
control the devices.
2
3
If two or more devices
have the same ID
number, both units will
respond to the same
MMC commands.
Some devices can respond
to multiple ID numbers.
ID number 127 is referred to
as the “All-Call ID Number”.
MMC commands sent with
this ID will control all MMC
devices in the set-up
regardless of their unique ID
number (if they are
programmed to do so).
It is also possible to create a
group ID number that
represents multiple devices.
This means that a single
command can be sent to
specific a group of devices
instead of a message for each
device.
There are two types of
MMC messages:
o Command
o Response
It is possible to ask an MMC device
for its identity. To do so, you send the
device an ID Request message.
The reply is device/manufacturer
specific.
Parts of ID message:




Device's ID
Device's family code
Device's family number
Software Version
MMC Handshake
closed loop VS open loop
Most MMC devices when turned on
determine if there is two-way
communication (closed-loop) or
one-way communication (open
loop).
MMC Handshake
closed loop VS open loop
open
MMC Handshake
closed loop VS open loop
closed
MMC Handshake
closed loop VS open loop
If a device doesn’t detect a closedloop, it assumes that it will only
send or receive MMC commands
rather than doing both.
MMC Handshake
closed loop VS open loop
If the device receives a ‘handshake’, it assumes that it can do
both, transmit and respond to MMC
commands and responses.
MMC works with MTC / MIDI Clock / Etc
The Goto MMC message
The Goto message cues recording or
playback to a SMPTE time (a specific
hour, minute, second, SMPTE frame
number, and subframe number)
SPP can be used.
Identity Request
Query an MMC device to find
out its identity. Identity
Request message (note that
this is equal to a 'stop'
message)
The Record Ready MMC message
The Record Ready (Arm Tracks)
message will record-enable tracks
Classified by type:
Comm: Communications
Ctrl: Transport (play - stop - etc.)
MMC
Evnt: Event
MESSAGES
Gen: Time Codes
I/O: Reading, writing
Sync: Synchronization
MMC Messages (cont.)
Math: Mathematical operations
MTC: MIDI Time Code
Proc: Procedures
Time: info dealing with time
code
07 Record Exit (Punch out)
08 Record Ready
09 Pause
0A Eject
0F MMC Reset
40 Write
44 Locate/Go to
controls
01 Stop
02 Play
03 Deferred Play
04 Fast Forward
05 Rewind
06 Record Strobe (Punch In)
08 Record Ready
09 Record Pause
0A Eject
0B Chase (Sync)
0C Command Error Reset (I/O)
0D MMC Reset
40 Write (I/O)
42 Read
43 Update
44 Locate
46 Search
47 Shuttle
48 Step
4A GENERATOR COMMAND
4B MTC Command
4C Move (math affects time code)
4D Add (math affects time code)
4E Subtract (math affects time code)
4F Drop Frame Adjust (math affects
time code)
63H VITC insert enable
65H Failure
7CH Wait
75H Resume
MMC
RESPONSES
• record status
• track record status
• track record ready
• play speed reference (internal or
external)
• chase mode
• event response (did it do the command)
• failure
MIDI SHOW CONTROL
MSC
all types of entertainment control
devices to talk with each othe
MIDI SHOW CONTROL
MSC
• go
fire
• stop
all_off
• resume
restore
• timed_go
reset
• load
go_off
• set
MIDI SHOW CONTROL
MSC
The first show to fully utilize the MSC
specification was the Magic Kingdom
Parade at Walt Disney World's Magic
Kingdom in September 1991
Other Messages
• ACK
• NAK
• Cancel
• Wait
• End of File (EOX)