Specifications

Chapter 4: Using SYNC I/O 47
Compensating for Time Code
Offsets
You can offset the display of incoming time
code in the Pro Tools application. This is useful
when you want to adjust the display of time
code to match the start time of the session (such
as with source material that starts at a different
time), or compensate for source material that is
consistently offset by a fixed number of frames
(such as with some color–corrected video mas-
ters).
Pro Tools provides three different types of Ses-
sion Start Offsets settings (External Time Code
Offsets in Pro Tools 6.6.x). These offsets include:
• MMC (MIDI Machine Control)
• 9-Pin (Serial machine control)
• Synchronization peripherals such as the
SYNC I/O, USD, or other peripherals (such
as MIDI interfaces that provide MIDI Time
Code).
Unique values can be defined for each of these
three types offsets, or you can link all three to
adjust in unison.
Positive and negative offset values can be en-
tered to offset Pro Tools time code display later
or earlier, respectively.
Offsets and Time Code Display
The SYNC I/O Time Code Display continues to
display actual incoming time code, regardless of
any Session Start Offsets (External Time Code
Offsets in Pro Tools 6.6.x) that are applied in
Pro Tools.
To apply an offset to the session start time:
■ In the Session Setup window, in the Session
Start Offsets section (External Time Code Offsets
section in Pro Tools 6.6.x), enter a time in an
offset field.
To apply the same session start time to all
devices:
■ In the Session Setup window, select Link to
apply the same offset value to all devices.
Generating & Regenerating
Time Code
SYNC I/O generates LTC, VITC, and MTC simul-
taneously, obtaining time addresses from a vari-
ety of sources:
• When the Positional Reference is set to Gen-
erate, SYNC I/O generates LTC, VITC, and
MTC from an internal time address clock. This
is referred to as Generator Preset mode.
• When the Positional Reference is LTC, VITC,
or Bi-Phase, SYNC I/O generates LTC, VITC,
and MTC based on the time address of one of
those sources. This is sometimes called regen-
eration or translation. For SYNC I/O, this is re-
ferred to as Read/Regeneration mode.
Read/Regeneration Mode
In this mode, SYNC I/O regenerates time code
based on external positional reference informa-
tion (LTC or VITC time code, or a Bi-Phase/Tach
signal). Subject to certain conditions, three
types of time code (LTC, VITC, and MTC) are si-
multaneously regenerated from the selected po-
sitional reference.
Time code generated by the SYNC I/O does
not follow session Pull Up and Pull Down
settings.