User guide

USING CLOCKWORKS FOR MAC OS X WITH THE MIDI TIMEPIECE AV 11
Figure 16: Frame Lock and other check box options.
If the Frame lock option is turned on (checked), and the MIDI
Timepiece AV detects more than five frames in a row that are not
continuous with respect to previous frames received, then it will
stop converting altogether.
If the Frame lock option is turned off (unchecked), and the MIDI
Timepiece AV detects more than five frames in a row that are not
continuous with respect to previous frames received, then it
begins to perform a kind of “pseudo jam sync”. In this mode, it
continues to convert an uninterrupted stream of continuous time
code, while at the same time clocking off of the incoming time
code. Even though the frames it is generating no longer match the
frames it is reading, it will continue to remain in sync with the
incoming time code.
In other words, when the Frame lock option is off, the MIDI
Timepiece AV ignores discontinuous jumps in incoming time
code by continuing to clock itself off of the incoming time code
without stopping (or pausing). In doing so, it continues to convert
a continuous, uninterrupted stream of frame times based on the
time code to which it first locked.
Tur n on Fr a me lock when you want the MIDI Timepiece AV’s
frame times to match incoming frame times, and you want it to
stop converting altogether if there are jumps in incoming time
code.
Tur n ing off Fr ame lock c an be a life saver if you find yourself in a
situation where you have time code on tape (or other source) but
the frame locations jump around to different times (because of
overlapping SMPTE striping, edits, or whatever). By turning off
Frame lock, you can sync continuously to this type of time code
without glitching or stopping. If the SMPTE on your tape jumps
around as described, you are likely to experience brief drop-outs
at the points where it jumps. If so, just increase the MIDI
Timepiece AV’s freewheeling to cruise past them.
Generate signal when stopped
This option applies to situations in which the MIDI Timepiece AV
is converting time code and the source time code continues even
when it is parked on a frame. The most common case is when the
MIDI Timepiece AV is locked to VITC (via a synchronizer that
can read vertical interval time code), and the video deck is paused.
In this situation, the Generate signal when stopped option, when
checked, makes the MIDI Timepiece AV continue to output time
code (LTC and MTC), even while the video is parked on a single
frame in pause mode. It will continue to do so as long as the video
head is engaged and VITC lines can be scanned.
Auto-detect input frame rate
When this option is checked, the MIDI Timepiece AV will
automatically detect the frame rate of incoming SMPTE time
code (LTC or MTC). In most situations, this is desirable because it
ensures that the MIDI Timepiece AV is properly interpreting and
synchronizing to the time code. If, however, you find yourself in a
situation where you would like to set the frame rate manually,
uncheck this option and set the frame rate in ClockWorks (or via
the front-panel LCD).
Enable automatic ADAT detection
When this option is checked (the default setting), the MIDI
Timepiece AV continuously polls its ADAT port for the presence
of an ADAT. If you plug one in and turn it on, the MIDI Timepiece
AV w i l l d e t e ct it and perform its routine handshake with the
ADAT (or any ADAT device on the ADAT sync chain).
Some ADAT-sync compatible devices do not respond well to this
sort of continuous polling. If your ADAT device or ADAT sync
chain is not behaving normally, try unchecking this box.
Always send ADAT commands
When this option is checked, the MIDI Timepiece AV will send
sync commands to its ADAT SYNC OUT port, regardless of
whether an ADAT device has been detected or not.
When this option is unchecked, the MIDI Timepiece AV only
sends sync commands to the ADAT port when an ADAT dev ice is
detected. If no ADAT device is detected, it sends nothing.
Check this option when you have connected the MIDI
Timepiece AV ADAT SYNC OUT port directly to a MOTU
PCI-324 or PCI-424 card SYNC IN port, with no ADATs in
between.
Enable Superclock
The Enable Superclock option changes the MIDI Timepiece AV
word clock output to Digidesign 256x “superclock” instead of
standard 1x word clock.
Lock word clock to video
When the Lock Word Clock to video option is checked, the MIDI
Timepiece AV derives its time base from a video signal present on
its VIDEO SYNC IN connector. This is equivalent to choosing one
of the three VIDEO timebase modes in the MIDI Timepiece AV’s
front panel LCD.
MIDI Machine ID
The MIDI Machine ID option lets you change the MMC (MIDI
Machine Control) device ID of the MIDI Timepiece AV. The
factory default ID of the MIDI Timepiece AV is 20. The only
situation in which you really need to change it is if you are using
MIDI Machine Control with two or more MIDI Timepiece AVs.
Otherwise, just leave it set to 20, and make sure that your MMC
transport master controller device or computer software knows
that the MIDI Timepiece AV’s ID is 20.