Specifications

192 Digital I/O Guide18
If at least two channels are not assigned from
the selected digital port in the Main page of the
Hardware Setup dialog, or if no valid clock
source is detected at this port, 192 Digital I/O
will switch to INT and the DIG LED will flash.
LOOP (Loop Master) This LOOP LED indicates
that the 192 Digital I/O is synchronized to an-
other HD I/O through Loop Sync.
You do not set LOOP mode anywhere in the
software; this is done automatically when you
choose a particular I/O as LOOP MASTER by se-
lecting a Clock Source from that I/O. Once you
set this, all other peripherals in the chain will
automatically be set for Loop Slave and light the
LOOP LED.
Because you can select any HD I/O in the chain
to be Loop Master, you can use the digital or Ex-
ternal Clock ports for synchronization on any
peripherals without having to physically change
any of the synchronization connections.
EXT (External) This setting indicates that
192 Digital I/O is using the EXT CLOCK IN port
for system synchronization. External Clock in-
put and output do not have to be at the same
rate as Word clock.
EXT CLOCK IN synchronization will typically
be 1x the current session sample rate. However,
for sample rates higher than 48 kHz,
192 Digital I/O will generate a choice of 1x or a
base rate of 44.1 kHz or 48 kHz, depending upon
the higher rate, as follows:
For a more detailed explanation of synchroniza-
tion mode and External Clock issues, see the
Getting Started with HD Guide.
By default, until you select another HD I/O
by selecting its Clock Source, the Loop Mas-
ter will be the HD I/O connected directly to
the HD Core card.
Session Sample Rate Word Clock Support
44.1 kHz 44.1 kHz
(256x out only)
48 kHz 48 kHz
(256x out only)
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