Model 5402 User Guide Issue 4, August 2021
Studio Technologies, Inc. Page 7
Model 5402
DANTE LEADER CLOCK WITH GNSS SYNCHRONIZATION
An active, multi-band, high-precision antenna is in-
cluded with each Model 5402. The compact antenna
is weather-resistant and includes a 5-meter (16.3 foot)
cable with attached SMA plug. The antenna can be
secured to the selected location using two machine
screws or affixed magnetically to a metallic surface.
Its performance is very good and many applications
will find this antenna to be sufficient. But it’s expected
that alternate, installer-provided antennas may also be
utilized to meet the specific needs of various applica-
tions. This may involve supporting longer interface
cables, using different mounting methods, or providing
more-advanced weather-resistant properties.
Word Clock Output
The Model 5402 generates a precise word clock
output signal that can be used as a timing reference
for related equipment. It’s specifically intended for
“locking” digital audio devices in applications that use
the Model 5402 to provide timing reference signals
for the associated Dante equipment. In this way, all
devices in an installation will share a common timing
reference.
The word clock output rate can be 44.1, 48, 88.2,
96, 176.4, or 192 kHz. The underlying timing source
for the word clock output is derived from the Model
5402’s main timing source. This will typically be one
or more of the supported GNSS constellations. The
main timing source is divided and processed by the
Model 5402’s logic circuitry to create the highly stable
word clock output. This ensures that the word clock
output is synchronized with the unit’s PTPv1 and
PTPv2 server functionality.
Audio Tone Generator
The Model 5402 generates eight sine wave audio
tones intended for general-purpose use. These audio
tones are provided by the Model 5402 in the form of
Dante transmitter (output) channels. They can be
connected, using the Dante Controller application, to
Dante receivers (inputs) on related equipment. The
flexibility of being able to interconnect signals (create
Dante “subscriptions”) between all Dante devices on
a network allows the audio tones to be used for a
variety of purposes. Configuration choices allow the
frequency and level of each sine wave tone to be
optimized for use in specific applications.
Leader Clock Support for Dante Networks
A core part of the technology underlying Dante audio-
over-IP networking ensures that all connected devices
follow a common timing reference. This is accom-
plished using the IEEE 1588-2002 (PTPv1) and 1588-
2008 (PTPv2) precision time protocols. Any connected
Dante device can be used as a Leader clock; there is
no requirement that a dedicated Leader clock device
be utilized to realize adequate functionality. However,
the actual performance can vary widely depending on
the specific Dante devices available and the overall
number of Dante devices on a network.
Many Dante devices utilize the 2- or 4-channel
Ultimo™ ULT or UXT integrated circuits to implement
Dante connectivity. While Ultimo devices will fully sup-
port Dante audio transport, they are not well suited to
serve as a Leader clock. Ultimo’s PTP performance
is limited and does not have the ability to synchro-
nize with an external timing reference. Other Dante
devices may use the Brooklyn II module or Broadway
integrated circuit to support Dante connectivity. In
some cases, these devices can provide good basic
performance as a Leader clock.
However, problems and limitations may arise when
these devices are called upon to perform “double
duty,” serving in both a primary function (such as
analog-to-Dante interfacing or audio signal process-
ing) as well as acting as a Leader clock. This is un-
derstandable as the main purpose of these devices
is to serve functions other than acting as a primary
synchronization reference. Specialized features, such
as allowing a GNSS-derived time base are rarely, if
ever, supported. PTP performance can degrade when
the computing power of a device is intended primarily
for handling and manipulating digital audio signals.
This can lead to the required PTP resources being
in short supply when the number of Dante devices
that need timing messages moves into the hundreds.
Also, firmware updates, cabling changes, and other
maintenance tasks typically associated with a general-
purpose Dante device would impact the Leader clock
functionality for an entire installation.
The Model 5402 was specifically designed to support
a Dante-based audio or video system’s Leader clock
requirement. By utilizing GNSS, multiple Model 5402
units can be installed at independent locations while
