Avid HD OMNI Preamp, I/O, and Monitoring Pro Tools HD Series Interface - Manual (Page 12)

HD OMNI Guide 8
Sync Mode LEDs
The SYNC MODE LEDs indicate the current
Clock Source as set in the Pro Tools Hardware
Setup (see “Pro Tools Hardware Setup” on
page 25) or on HD OMNI in SETUP mode (see
“Clock Source (CLOCK)” on page 49).
INT (Internal) Indicates the HD OMNI sample
clock is generated by its internal crystal oscilla-
tor, as determined by the session Sample Rate.
EXT (External) Indicates that the HD OMNI is ei-
ther using the EXT CLOCK IN port or a digital
source for system synchronization.
When synchronized to Word Clock, External
Clock input and output do not have to be at the
Word clock rate. At 44.1 kHz and 48 kHz, EXT
CLOCK IN synchronization will be 1x the cur-
rent session sample rate. However, for sample
rates higher than 48 kHz, HD OMNI generates a
choice of 1x, 2x, or 4x of a base rate of 44.1 kHz
or 48 kHz, as follows:
LOOP Indicates that the HD OMNI is slaving to
another Pro Tools|HD audio interface using
Loop Sync.
MST (Loop Master) Indicates which Pro Tools
audio interface is the master Pro Tools periph-
eral. The Loop Master LED will be continuously
lit on the current Loop Master peripheral only,
and unlit on all other peripherals. (Only one
Pro Tools audio interface can be Loop Master at
a time.) The Loop Master LED will always be lit
with a single interface.
For Pro Tools|HD systems, Loop Master defaults
to the first Pro Tools audio interface connected
to the primary, or “core” Pro Tools|HD card.
Sample Rate LEDs
These LEDs display the current sample rate of
the HD OMNI internal crystal oscillator:
44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz,
or 192 kHz. The sample rate can be set in
Pro Tools when you create a new session, or in
the Hardware Setup (see “Pro Tools Hardware
Setup” on page 25) or Playback Engine dialogs if
no session is open. You can also set the Sample
Rate in SETUP mode if Pro Tools is not running
(see “Internal Sample Rate (SRATE)” on
page 49).
Session Sample Rate Word Clock Support
44.1 kHz 44.1 kHz
48 kHz 48 kHz
88.2 kHz 88.2 kHz
44.1 kHz
96 kHz 96 kHz
48 kHz
176.4 kHz 176.4 kHz
44.1 kHz
192 kHz 192 kHz
48 kHz
The Word Clock base rate can only be set in
the Pro Tools Hardware Setup.
If the EXT LED flashes on and off,
HD OMNI does not have external sync.
Check to make sure that HD OMNI is re-
ceiving synchronization from the correct
clock source.