Specifications

Chapter 2: Expanded Pro Tools|HD Systems 11
3 Connect the External Clock Out of the pri-
mary interface to the Slave Clock In of the Leg-
acy audio interface using a BNC cable.
4 If connecting two Legacy peripherals, connect
the Slave Clock Out of the first Legacy periph-
eral to the Slave Clock In of the second Legacy
peripheral.
Identifying Audio Interfaces
If you have multiple audio interfaces of the
same type connected to your system, you can
confirm the identity of each interface. This en-
sures that you choose the appropriate interface
in the Peripherals list when you define its inputs
and outputs in the Hardware Setup dialog.
To identify audio interfaces in your system:
1 Choose Setup > Hardware.
2 From the Peripherals list, select an audio inter-
face connected to your system.
3 Click Main.
4 Select the Identify option, located in the lower
left corner of the Hardware Setup dialog. This il-
luminates all the LEDs on the front panel of the
selected audio interface.
5 Make a note of which interface in your studio
setup corresponds to the identified interface.
6 Repeat the above steps for each additional au-
dio interface in your setup.
Number of I/O Channels in
Expanded Systems
You can add audio interfaces to your system to
increase the number of available channels of
hardware input and output. Hardware input
and output includes digital and analog connec-
tions.
Number of Channels of I/O
Pro Tools|HD audio interfaces provide varying
numbers of hardware input and output connec-
tors and ports, a certain number of which can be
utilized simultaneously.
The 96 I/O and standard 192 I/O are examples of
symmetrical I/O, where there are the same num-
ber of input channels as output channels. For
example, there are 8 analog inputs and 8 analog
outputs. Though these I/Os provides many ana-
log and digital connectors on their back panels,
they support a total of 16 channels of simulta-
neous, discrete input and output. This means
you can be listening to or recording as many as
16 channels of input while simultaneously
monitoring or sending as many as 16 channels
of output through a single I/O.
The 192 I/O can be expanded by adding a
192 A/D or 192 D/A Expansion card to increase
the number of analog inputs or analog outputs
to 16. Expanded 192 I/O interfaces are an exam-
ple of asymmetrical I/O when they have a differ-
ent number of input channels or output chan-
nels. For example, when a 192 A/D card is
installed on a standard 192 I/O, the I/O now has
16 analog inputs and 8 analog outputs.
On Expanded 192 I/Os, the maximum number
of simultaneous, discrete inputs and outputs is
still 16.
Do not connect the Slave Clock Out of the
last Legacy peripheral to the clock input on
any Pro Tools|HD interface.
If using an 888|24 I/O, do not power on the
888|24 until you are ready to declare it in
the Hardware Setup dialog, after launching
Pro Tools. See the Pro Tools|HD Getting
Started Guide for more information.
For specifications of Pro Tools|HD I/Os, refer
to the Pro Tools|HD Getting Started Guide.