MOTU micro express-USB, User Manual

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CHAPTER
131
13
MIDI Machine Control with the AV
OVERVIEW
The MIDI Timepiece AV can serve as a MIDI
Machine Control (MMC) transport control “hub”
for ADATs and all other connected devices,
allowing you to manipulate the transport controls
of everything from one master set of controls:
either an Alesis LRC (or LRC-compatible device)
connected to the front panel of the MIDI
Timepiece AV, or from MMC-compatible MIDI
software on the computer.
How MMC works . . . . . . . . . . . . . . . . . . . . . . . . .131
Setting MMC device ID’s . . . . . . . . . . . . . . . . . . .132
Setting up other MMC devices . . . . . . . . . . . . . .132
MMC remote control of record functions . . . .134
Using a third-party MMC device as a master .134
MMC routing example. . . . . . . . . . . . . . . . . . . . .134
Using an Alesis LRC . . . . . . . . . . . . . . . . . . . . . . .135
HOW MMC WORKS
MIDI Machine Control involves all three
components of synchronization:
■
time base
■
address
■
transport control
An MMC controller (which has transport and
cueing controls) sends transport commands (play,
stop, cue, etc.) to an MMC device that is serving as
a time code (address) source. When the MMC
device responds to the transport commands, it
generates time code (address) information to
which all other devices chase and lock. The other
devices do not need to be MMC devices, as they
sync in the usual fashion via time code (LTC or
MTC).
The MMC device (address source) may also serve
as the time base master, but in a MIDI
Timepiece AV-based studio, it doesn’t necessarily
have to. For example, video house sync could
provide the time base, while the MIDI
Timepiece AV provides address (time code).
A recommended setup for MMC
The best scenario for MMC is to set the MASTER
SYNC setting in the MIDI Timepiece AV to
INTERNAL or INTERN/VIDEO. In either case,
the MIDI Timepiece AV serves as the address
master, and your computer software (or Alesis
LRC-compatible hardware connected to the
MTP AV front panel) serves as your MMC
transport control master. The MMC controller
sends play, stop, start and cueing commands to the
MIDI Timepiece AV, and all other devices
(including the computer software) chase and lock
to time code being generated by the MIDI
Timepiece AV. In this scenario, time base is
provided either by the MIDI Timepiece AV or by
incoming video sync.
Other MMC scenarios
In the recommended scenario described in the
previous section, the MIDI Timepiece AV receives
MMC transport commands and serves as the time
code (address) master for everything else.
Alternately, you could choose another MMC
device to receive transport commands and serve as
the time code master. For example, the device
would receive transport commands from your
computer software and generate SMPTE time code
(LTC). In this case, you would set the MIDI
Timepiece AV MASTER SYNC setting to LTC and
feed the LTC into the MIDI Timepiece AV, which
would then drive all other devices.
!USB Interfaces Manual Book Page 131 Tuesday, October 10, 2000 12:43 PM