Specifications

SYNC I/O Guide16
The Clock Source menu follows your selection
of SYNC I/O for Clock Reference, and automati-
cally switches to SYNC I/O. (You can also
choose the SYNC I/O as Clock Source first, then
select a Clock Reference.)
To choose a different Loop Sync device as the
Clock Source:
■ Choose a different Loop Sync device and
Clock Source from the hierarchical Clock Source
menu.
When Clock Source is an HD I/O
When a 192 I/O, 192 Digital I/O or 96 I/O is pro-
viding the Clock Source, it will be the Loop Mas-
ter. Clock Source options are available directly
from the Clock Source menu, based on the con-
figuration of that interface in the Hardware
Setup dialog. Choices can include AES, S/PDIF,
Optical, or Word Clock.
Locked and Speed Cal LEDs
The Locked and Speed Cal indicators in the
SYNC I/O section of the Session Setup window
display synchronization status of the SYNC I/O.
These indicators reflect the state of the same
LEDs on the front panel.
Locked The Locked indicator stays lit when the
SYNC I/O is locked to the selected clock refer-
ence. The Locked indicator flashes if the selected
clock reference source is missing or out of lock-
able frequency range.
Speed Cal Speed Cal is an indicator of the accu-
racy of the incoming clock reference. The Speed
Cal indicator flashes when the output sample
rate is not at the expected (or target) rate. The
Speed Cal indicator stays lit when the output
frequency is within 200 ppm (0.02%) of the se-
lected sample rate. If the output frequency is
higher than expected, the Speed Cal indicator
flashes quickly; if the output frequency is lower,
the Speed Cal indicator flashes slowly.
For example, if the session is 30 fps and LTC is
the selected clock reference but the LTC is actu-
ally 29.97, the SYNC I/O will lock (the Locked
LED will stay lit), but the Speed Cal LED will
flash slowly.
Positional Reference
To select a positional reference:
1 Choose Window > Show Session Setup.
2 Choose a positional reference from the Posi-
tional Reference menu, located in the SYNC
Setup controls.
Choosing a Clock Source
Selecting a Clock Source option on a 192 I/O
See the Getting Started with HD Guide for
more information on audio interface config-
uration.
Locked and Speed Cal Indicators