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MIDI MACHINE CONTROL

Other MMC scenarios

In the recommended scenario described in the previous

section, your Express interface receives MMC transport

commands and serves as the time code master for

everything else.

Alternately, you could choose another MMC device, such

as a hard disk recorder, 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 your Express interface master sync

mode to LTC QuikLock and feed the LTC into your Express

interface, which would then drive all other devices.

There is no advantage to doing MMC this way; in fact, it

will probably not provide as stable a time base as your

Express interface does in the recommended scenario

described in the previous section. You should only really

use this setup if you have a MMC device that does not have

the ability to be a time code slave and therefore must be the

master.

MMC and video

If you are working with video, and you want MMC control

of your rig from your computer software (or MMC-

compatible controller) via your Express interface, your

video deck needs to have the ability to either:

■ Synchronize to external SMPTE time code

■ Support MMC

Without either of these capabilities in your video deck,

your Express interface has no way to control the video

deck transports. You’ll instead have to use your video deck

as the transport and time code master.

If your video deck supports the SONY 9-PIN protocol,

consider purchasing MOTU’s video interfaces, which let

you control your video deck from a computer (or other

MMC controller).

!USB Interfaces Manual Book Page 66 Tuesday, August 16, 2011 11:21 AM