Studio Technologies 5401A User manual

50701-0721, Issue 2
Copyright © 2021 by Studio Technologies, Inc., all rights reserved
studio-tech.com
User Guide
Issue 2, July 2021
This User Guide is applicable for serial numbers
M5401A-01001 and later with Main MCU Firmware 1.04 and later
Model 5401A
Dante® Leader Clock

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Model 5401A User Guide Issue 2, July 2021
Studio Technologies, Inc. Page 3
Table of Contents
Revision History ................................................................................................................. 4
Introduction ......................................................................................................................... 5
Installation .......................................................................................................................... 9
Dante Configuration ........................................................................................................... 12
Model 5401A Configuration ................................................................................................ 15
Operation ............................................................................................................................ 29
Technical Notes .................................................................................................................. 40
Specifications ..................................................................................................................... 45
Appendix A–Compatible Sync Input Sources ..................................................................... 47
Appendix B–Network Configuration Examples ................................................................... 48
Appendix C–Dante Controller Network Default Configuration Values ................................ 51
Appendix D–Menu Structure .............................................................................................. 52
Appendix E–Screen Captures ............................................................................................ 53
Appendix F–Model 5401A Default Configuration Values .................................................... 58
Appendix G–PTPv2 (IEEE® 1588-2008) Default Characteristics ...................................... 59
Appendix H–Accessing the Unit when User Name and/or Password are Not Known ....... 60

Issue 2, July 2021 Model 5401A User Guide
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Revision History
Issue 2, July 2021:
• Documents support for 176.4 and 192 kHz sample rates.
• Miscellaneous corrections and clarifications.
Issue 1, May 2021:
• Initial release.

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Introduction
The Model 5401A Dante Leader Clock pro-
vides precise timing signals for applications
that utilize the Dante audio-over-IP media
networking technology. The unit implements
a high-performance IEEE® 1588 precision
time protocol (PTP) server, compatible with
the requirements of Dante and capable of
simultaneously supporting the timing needs
of up to hundreds of Dante-compatible
devices. As expected, the Model 5401A
provides the PTPv1 (IEEE 1588-2002)
compatibility that’s required by Dante.
In addition, the unit supports PTPv2 (IEEE
1588-2008) for AES67 applications. A word
clock output provides a general-purpose
timing reference for use by external devic-
es. The Model 5401A also generates eight
sine wave audio tones on Dante transmit-
ter (output) channels which can be useful
during audio and data network installation,
maintenance, and operation. A sync input
connection allows the Model 5401A’s in-
ternal oscillator to be synchronized with a
variety of timing and reference signals.
The Model 5401A is suitable for use in fixed
and mobile broadcast facilities, post-pro-
duction studios, commercial and education-
al theater environments, and entertainment
applications. Only power and one, two, or
three Ethernet network connections are
required for full operation. Using Dante’s
inherent capabilities two Model 5401A units
can serve in primary and backup Leader
clock roles for redundant operation.
The unit’s three Gigabit Ethernet (GigE)
network interfaces can be configured for
use in a range of network implementations.
For high-reliability audio applications two
of the interfaces can support Dante redun-
dancy operation while the third is used for
accessing the management webpages. To
meet the latest interoperability standard the
Model 5401A’s Dante implementation sup-
ports AES67-2018. The unit also integrates
with the Dante Domain Manager™ (DDM)
software application.
An integrated web server allows fast and
flexible monitoring and configuration of
the unit’s networking, clocking, and Dante
performance. Front-panel LED indicators,
an LCD display, and pushbutton switches
provide users with direct access to key
operating parameters.
The Model 5401A can be powered by 100-
240 V, 50/60 Hz mains or a source of 12
volts DC. Both can be simultaneously con-
nected to provide redundant operation. The
lightweight enclosure mounts in one space
(1U) of a 19-inch equipment rack. Industry-
standard connectors are used for Ethernet,
DC power, and AC mains interconnections.
Updating the Model 5401A’s operating
software can be easily performed using a
standard USB flash drive.
Figure 1. Model 5401A Dante Leader Clock front and back views

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Applications
Applications for the Model 5401A include
broadcast and post-production facilities,
college and university audio networks, are-
nas, stadiums, corporate installations, and
virtually any application where substantial
numbers of Dante-compatible devices are
utilized. The Model 5401A will serve as a
stable and consistent Leader clock for the
entire Dante “network.” And, as expected,
the Model 5401A is compatible with all
Dante devices, no matter what their function
or manufacturer. Applications that utilize
devices compatible with AES67 will also
benefit from the Model 5401A’s resources.
Why a Dedicated Dante
Leader Clock?
With Dante ubiquitous in fixed and mobile
facilities of all sizes and types, the need
arose for a cost-effective, purpose-
designed, dedicated Leader clock. While
an inherent strength of Dante networking
is its carefully implemented use of the IEEE
1588 standard to ensure that all connected
devices maintain a common timing refer-
ence, the actual performance can vary
widely depending on the specific Dante
devices in use and the overall number of
devices on a network. There are many
Dante-compatible devices that can provide
adequate basic performance as a Leader
clock, but with the Model 5401A networked
audio systems get the benefits of a high-
performance Primary Leader Clock, along
with additional unique capabilities. The
unit’s feature set, along with the associ-
ated internal hardware and software, was
designed to provide optimum performance,
flexibility, and system integrity.
Timing Sources
The Model 5401A can provide excellent
Leader clock performance using its tem-
perature- stabilized internal oscillator, which
exceeds the capability of standard Dante
devices by at least an order of magnitude.
While its standalone performance is excel-
lent, the Model 5401A can also be “locked”
to a variety of external signals for integra-
tion into facilities that include a central or
main timing reference. Compatible signals
include word clock, video reference, and
10 MHz.
Word clock is a square wave signal that is
often used as a timing reference in audio-
only facilities. Several common word clock
rates, including 48, 96 kHz, and the more-
exotic 192 kHz, are compatible with the
Model 5401A’s sync input. Video reference
(“sync”) signals are found in most broadcast
and post-production facilities. The Model
5401A supports the most-common video
format/rate combinations including “black
burst,” bi- and tri-level HD, and several that
are specifically intended for 4K applications.
Industrial and commercial facilities often uti-
lize a GPS-disciplined source of 10 MHz as
a timing reference. This sine wave signal is
typically compatible with the Model 5401A’s
sync input.
Word Clock Output
The Model 5401A 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 5401A 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 5401A’s main timing
source. As previously reviewed, the internal
oscillator, if desired, can be “locked” to an
external source. The main timing source
is divided and processed by the Model

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5401A’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 func-
tionality.
Audio Tone Generator
The Model 5401A generates eight sine
wave audio tones intended for general-pur-
pose use. These audio tones are available
from the Model 5401A by way of Dante
transmitter (output) channels and can be
connected, using the Dante Controller ap-
plication, 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. Configura-
tion 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 com-
mon timing reference. This is accomplished
using the PTPv1 (IEEE 1588-2002) and
PTPv2 (IEEE 1588-2008) 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 func-
tionality. 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 connectiv-
ity. While Ultimo devices will fully support
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 synchronize 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 perfor-
mance 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 processing) 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 act-
ing as a primary synchronization reference.
Timing related features, such as allowing
connection of a video bi- or tri-level sync
signal is rarely, if ever, supported. And PTP
performance can degrade when the com-
puting power of a device is intended pri-
marily 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 asso-
ciated with a general-purpose Dante device
would impact the Leader clock functionality
for an entire installation.
The Model 5401A was specifically designed
to support a Dante-based audio system’s
Leader clock requirement. And the unit’s
generation of audio tones and implementa-
tion of the word clock output utilize hard-
ware circuitry that is separate from that
associated with its PTP functionality. As
such, this secondary functionality will not
interfere with PTP operation. Unlike a
general-purpose Dante device, once mount-
ed in an equipment rack and the required

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interconnections are made, the Model
5401A will perform its tasks without risk
of interruption due to conflicting resource
demands.
Flexible Networking
Capability
Using the Dante Controller application
program, the Model 5401A’s three Eth-
ernet ports can be selected to operate in
one of four modes: Switched, Redundant,
Switched+Mgmt, and Redundant+Mgmt.
This should allow virtually any desired
networking implementation to be easily
achieved.
By using the Switched or Redundant net-
work modes, separate network connections
will be maintained for Dante audio and
management purposes.
In the Switched mode a single Ethernet
connection to either of the Model 5401A’s
two Dante Ethernet ports will provide Dante
Leader clock functionality. The remain-
ing Dante Ethernet port will provide Dante
network “loop-through” capability and can
be used to interface with another piece
of Ethernet-connected equipment. The
management Ethernet port will be used to
access the Model 5401A’s monitoring and
configuration webpages.
In the Redundant mode two independent
Ethernet connections are made to the
Model 5401A’s two Dante Ethernet ports,
enabling Dante’s redundant networking
capability. Again, the management Ether-
net port will be used to access the Model
5401A’s monitoring and configuration
webpages.
In the Switched+Mgmt mode a single Ether-
net connection is used for both Dante Lead-
er clock functionality as well as providing
access to the Model 5401A’s management
webpages. The remaining Dante Ethernet
port will provide network “loop-through”
capability and can be used to interface
with another piece of Ethernet-connected
equipment.
In the Redundant+Mgmt mode two inde-
pendent Ethernet connections can be made
to the Model 5401A’s two Dante Ethernet
ports. This will enable Leader clock ca-
pability for applications that utilize Dante
redundancy. Access to the Model 5401A’s
management webpages will be made by
way of the Ethernet connection made to the
Dante primary Ethernet port.
Operating Power
The Model 5401A allows an AC mains
source of 100-240 V, 50/60 Hz to be directly
connected. It can also be DC powered us-
ing a 10-18 volt source that is connected via
a broadcast-standard 4-pin XLR connector.
If both AC and DC power sources are con-
nected the unit will be powered by the AC
mains supply. Only if the AC mains source
fails will appreciable power be drawn from
the DC source. This allows a source of DC,
typically an external power supply, to serve
in a backup capacity. With this arrangement
normal operation can continue even if AC
mains power is lost.
Future Capabilities
The Model 5401A was designed so that its
capabilities can be enhanced in the future.
A USB receptacle located on the unit’s
back panel, allows the three firmware files
(embedded software) to be updated us-
ing a USB flash drive. The Model 5401A’s
Dante firmware can be updated using one
of the unit’s Ethernet connections, helping
to ensure that the Dante capabilities remain
up to date. All software files and configura-
tion parameters are stored in non-volatile
memory.

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Installation
In this section the Model 5401A will be
mounted in one space (1U) of an equipment
rack. In many cases, an external synchroni-
zation source will be connected to the sync
input BNC jack. If needed, a connection may
be made to the word clock output BNC jack
on the back panel. One or more Ethernet
data connections will be made. AC mains
and/or DC power will be connected to the
Model 5401A.
Using a coaxial cable terminated with a BNC
plug, an external source of synchronization
may be connected to the sync input. A word
clock output is provided by way of a BNC
jack and may be utilized by one or more
pieces of equipment. Up to three Ethernet
data connections will be made to the Model
5401A using standard RJ45 patch cables.
AC mains power can be connected to the
Model 5401A by means of a detachable cord
that is compatible with the unit’s 3-pin IEC
320 C14 inlet connector. Some applications
may warrant connection to a source of nomi-
nal 12 volts DC which can be made by way
of a 4-pin XLR connector. A DC source can
be used to power the Model 5401A as well
as serving as a backup power source should
AC mains not be present.
What’s Included
The shipping carton contains a Model 5401A
Dante Leader Clock and instructions on how
to obtain an electronic copy of this guide.
Also included in the shipping carton is a
North-American-standard AC mains cord.
For destinations outside of North America
the local reseller or distributor should pro-
vide an appropriate AC mains cord.
Mounting the Model 5401A
The Model 5401A Dante Leader Clock re-
quires one space (1U) in a standard 19-inch
(48.3 cm) equipment rack. Secure the unit
into the designated equipment rack using
two mounting screws per side. As the Mod-
el 5401A does not contain a fan or other
noise-producing source it can be located
within a room or other structure where au-
dio monitoring is going to take place. Some
or all of the connections involving the sync
input BNC jack, the word clock output BNC
jack, the Ethernet interface RJ45 jacks, and
the AC mains and/or DC power connectors
may be utilized.
Twisted-pair (UTC) Ethernet has a 100-
meter (325-foot) interconnection cable limi-
tation. But that can be overcome by using
fiber-optic interconnections between the
Model 5401A and the Ethernet switch or
switches in the one or more associated
local-area-networks (LANs).
Sync Input
An external synchronization source can be
connected to the Model 5401A’s sync input
BNC jack. Located on the back panel, this
input allows the Model 5401A’s internal tim-
ing to be “locked” to an external reference.
Signals that are compatible with the Model
5401A’s sync input include word clock, bi-
level video, tri-level video, and 10 MHz sine
wave. A configuration setting in the Sync
Input webpage defines what type of signal
is going to be connected. Another setting
defines if a termination impedance is ap-
plied to the sync input. Refer to the Specifi-
cations section of this guide for the general
characteristics required of acceptable exter-
nal sync signals.
A connected word clock signal must be a
square wave with a rate that matches the
Dante sample rate as defined in the Dante
Controller application. The rate can be 44.1,
48, 88.2, 96, 176.4, or 192 kHz. If termina-
tion has been enabled for the sync input
when it has been configured for word clock
an impedance of 75 ohms will be applied.

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A source of bi-level or tri-level video can
also be connected to the sync input. Circuit-
ry within the Model 5401A will decode many
of the common video rates and formats, al-
lowing them to serve as a timing reference.
Refer to Appendix A, located at the end of
this guide, for a list of compatible rates and
formats. If the sync input is configured for
video and termination has been enabled an
impedance of 75 ohms will be applied.
A source of 10 MHz sine wave can be con-
nected to the Model 5401A’s sync input.
This type of signal is commonly used as
a timing reference in industrial and instru-
mentation applications. An impedance of 50
ohms will be applied to the sync input if ter-
mination has been enabled and the source
is selected for 10 MHz.
Word Clock Output
A word clock output signal is provided for
use by other devices that want to be “timed”
from the Model 5401A. Available by way
of a BNC jack located on the back panel,
the square wave output has a frequency
that matches the unit’s configured Dante
sample rate. Choices are 44.1, 48, 88.2, 96,
176.4, and 192 kHz. The exact frequency
of the word clock output is based on the
timing reference that has been selected for
the Model 5401A. If, for example, the Sync
Input was selected as the unit’s timing refer-
ence, then the word clock output would be
“locked” to it.
The source impedance of the word clock
signal is 75 ohms and its unterminated
output level is 5 volts peak-to-peak (Vpp).
When externally terminated with a 75 ohm
load the word clock output level will drop to
2.5 Vpp.
Ethernet Connections
The Model 5401A provides three Giga-
bit Ethernet (GigE) ports for flexibility and
compatibility with many networking imple-
mentations. Two ports are provided for
interconnections with one or two local area
networks (LANs) associated with Dante
audio-over-IP networking schemes. They
are labeled as PRI (primary) and SEC (sec-
ondary). The third Ethernet port, labeled
MGMT, can be used to access the Model
5401A management resources. An internal
web server function supports the Model
5401A’s management port’s webpages.
These webpages are used for configura-
tion, monitoring, and maintenance of Model
5401A operation. Refer to Figure 2 for an
overview of the Model 5401A’s three Ether-
net ports and how they can operate.
Using the Dante Controller application,
the three Ethernet ports can be config-
ured to operate in one of four modes:
Switched, Redundant, Switched+Mgmt, or
Redundant+Mgmt. If configured for either
the Switched or Redundant modes the
management webpages are accessed by
way of the management Ethernet port.
When configured for the Switched+Mgmt
mode the management webpages are
accessed by way of either the primary or
secondary Ethernet ports. When configured
for the Redundant+Mgmt mode the man-
agement webpages are accessed using an
Ethernet connection made to the primary
Ethernet port.
By providing three Ethernet ports and four
configuration modes, the Model 5401A al-
lows support for virtually all facilities, includ-
ing those that utilize separate networks for
Dante audio transport and equipment man-
agement. In this way, “production” networks
that support transport of audio signals by
way of a single LAN (Switched mode) or
two LANs (Redundant mode) can be sepa-
rate from an engineering network that is
used by technical personnel for configuring
and maintaining a facility or “plant.”

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Connections to the three Ethernet interfac-
es are made by way of standard RJ45 jacks
that are located on the back of the Model
5401A’s enclosure. The Ethernet interfaces
support auto MDI/MDI-X so that crossover
cables are not required. Refer to Appen-
dix B, located at the end of this guide, for
examples of how the Model 5401A’s three
Ethernet interfaces might be utilized. It’s dif-
ficult to conceive of a network environment
that the unit wouldn’t be able to effectively
support.
Dante Port Connections
At least one 1000BASE-T (GigE) Ethernet
connection is required for Model 5401A
Dante operation. It should be connected
to the primary RJ45 jack. A second
1000BASE-T (GigE) connection can be
made to the secondary RJ45 jack if Redun-
dant Dante is desired. For this functional-
ity to be active the Model 5401A’s network
configuration must be set for the Redun-
dant or Redundant+Mgmt mode within the
Dante Controller software application. While
technically 100BASE-TX (100 Mb/s) Ether-
net can also be used for these Dante con-
nections, it is not optimal. Additionally, it’s
important to note that 10BASE-T (10 Mb/s)
Ethernet connections are not sufficient.
When configured in Dante Controller for
the Switched or Switched+Mgmt modes the
Model 5401A’s Dante secondary Ethernet
connection can also be used as a “loop
through” port such as would be provided by
an Ethernet switch. Switched mode is the
default setting but using the Dante second-
ary port in this manner for applications other
than troubleshooting or “looping” to access
the Model 5401A’s management port is
not recommended. It will function reliably
but “daisy chaining” Ethernet signals can
limit flexibility and present a failure point;
it’s optimal if each Dante Ethernet interface
connects directly to a separate port on an
Ethernet switch.
Management Port Connection
If required by the needs of an application,
the management webpages can be ac-
cessed using an Ethernet signal connected
to the Model 5401A’s management Ethernet
port. This requires that the network mode in
Dante Controller be configured for Switched
or Redundant. It’s recommended that a
1000BASE-T (GigE) connection be made
but a 100BASE-TX (100 Mb/s) connection
is sufficient. (GigE will provide the best per-
formance and it’s assumed that all contem-
porary applications will support it.)
Access to the Model 5401A’s management
webpages can also be obtained using the
same network connection or connections
that are being used for Dante audio. This
requires that the network mode in Dante
Controller be configured for Switched+Mgmt
or Redundant+Mgmt. Appendix B provides
example of how these network scenarios
can easily be implemented.
Dante Controller Network Model 5401A Ethernet Port
Switch Configuration Pri Sec Mgmt
Switched Dante Management
Redundant Dante Primary Dante Secondary Management
Switched+Mgmt Dante and Management Disabled
Redundant+Mgmt Dante Primary and Management Dante Secondary Disabled
Figure 2. Model 5401A Ethernet Port Configuration and Operation

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Connecting Power
The Model 5401A requires a source of AC
mains or nominal 12 volts DC for operation.
Either source can be connected with the
same result. Both can also be simultane-
ously connected if a redundant (backup)
power scheme is desired.
Connecting AC Mains Power
The Model 5401A can operate directly
from AC mains power of 100 to 240 volts,
50/60 Hz, 5 watts maximum. As a “universal
mains input” device there are no switches
to set or jumpers to install. A 3-pin IEC
320 C14 inlet connector on the back panel
mates with a detachable mains cord set.
All units are supplied from the factory
with an AC mains cord that has a North-
American (NEMA 5-15L) standard plug on
one end and an IEC 320 C13 connector
on the other end. Units intended for use in
other destinations require that an appropri-
ate mains cord be obtained. The wire colors
in the mains cord should conform to the
internationally recognized color code and
be terminated accordingly:
Connection Wire Color
Neutral (N) Light Blue
Line (L) Brown
Earth/Ground (E) Green/Yellow
Because the Model 5401A does not contain
a power on/off switch it will begin operation
as soon as AC mains power is connected.
Safety Warning: The Model 5401A does
not contain an AC mains disconnect
switch. As such, the AC mains cord plug
serves as the disconnection device.
Safety considerations require that the
plug and associated inlet be easily ac-
cessible to allow rapid disconnection
of AC mains power should it prove
necessary.
Connecting DC Power
The Model 5401A can also operate from
a source of 10 to 18 volts DC. The current
required from a 12 volts DC source is 0.5
ampere (500 milliamperes) maximum. A
4-pin male XLR connector, located on the
unit’s back panel, is used to connect the
source of DC. Prepare a mating connec-
tor (female) so that pin 1 is DC– and pin
4 is DC+. Pins 2 and 3 are not used and
should remain unconnected. This connector
type and pinout have become a broadcast
DC power standard and should be familiar
to many technical personnel. Because the
Model 5401A contains no power on/off switch
it will begin operation as soon as a DC power
source is connected.
As previously mentioned, both an AC mains
source and a DC source can be connected
at the same time. If this is the implementation
then the AC mains source will always power
the Model 5401A with the DC source serving
as a “hot standby.” Only if the AC source fails
will the unit draw power from the DC source.
This will occur automatically with no interrup-
tion of Model 5401A operation. In this
“standby” mode (when an AC mains source
is connected) the Model 5401A draws less
than 110 microamperes (uA) from a 12 volts
DC input.
Dante Configuration
For audio and timing to correctly pass from
the Model 5401A requires that several Dante-
related parameters be configured. These
configuration settings are stored in non-
volatile memory within the Model 5401A’s
Dante network interface circuitry. Configu-
ration will typically be done with the Dante
Controller software application, available for
download free of charge at audinate.com.
Refer to Appendix C of the list of the Model
5401A’s Dante Controller default configura-
tion. Versions of Dante Controller are avail-
able to support several operating systems.

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The Model 5401A’s Dante interface is com-
patible with the Dante Domain Manager
(DDM) software application. Refer to DDM
documentation, also available from Audi-
nate, for details on which Model 5401A
and related parameters may have to be
configured.
Audio Routing
The Model 5401A’s eight Dante transmitter
(output) channels can be assigned to the
desired Dante receiver (input) channels on
associated equipment. This will route the
eight channels associated with the tone
generator function. Within Dante Controller
a “subscription” is the term used for routing
a transmitter flow (a group of up to four out-
put channels) to a receiver flow (a group of
up to four input channels).
The Model 5401A uses a Brooklyn II mod-
ule to implement its Dante functionality. The
number of transmitter flows associated with
this module is 32 and, as such, typically
no flow limitation should occur. These flows
can either be unicast, multicast, or a combi-
nation of the two. Note, however, that when
AES67 mode is enabled in Dante Controller
the Dante transmitter (output) channels will
only function in multicast; unicast is not
supported.
Unit and Channel Names
The Model 5401A has a default Dante
device name of ST-5401A- along with a
unique suffix. The suffix identifies the spe-
cific Model 5401A that is being configured.
The suffix’s actual alpha and/or numeric
characters relate to the MAC address of the
unit’s Brooklyn II module. The eight Dante
transmitter (output) channels associated
with the tone outputs have default names
of Tone 1 through Tone 8. Using Dante
Controller, the device and channel names
can be revised as appropriate for a specific
application.
Device Configuration
The Model 5401A supports audio sample
rates of 44.1, 48, 88.2, 96, 176.4, and 192
kHz with no pull-up/down options available.
The digital audio data is in the form of 24-bit
pulse-code modulation (PCM 24) samples.
Clocking- and latency-related parameters
can be adjusted if required in Dante Control-
ler but the default values are typically correct.
Network Configuration –
Dante
As has been covered previously in this guide,
the Model 5401A allows connection of one,
two, or three Ethernet signals using standard
RJ45 jacks which are located on the back
panel. In many applications, two of the jacks
will be used for Dante audio and the third
for connecting to a network designated for
device management purposes. It’s also pos-
sible to access the Model 5401A’s manage-
ment webpages using the Dante Ethernet
ports. The Model 5401A’s Dante ports are
labeled PRI and SEC indicating that they are
typically used for the primary and secondary
connections. The third Ethernet port is la-
beled MGMT, indicating that it is intended for
use accessing the management webpages.
How these three Ethernet ports function can
be selected in the Network Config – Switch
Configuration section of Dante Control-
ler. The choices are Switched, Redundant,
Switched+Mgmt, and Redundant+Mgmt.
If Switched is selected then the Model 5401A
can establish one Dante audio connection
with an Ethernet network. It doesn’t matter
which RJ45 jack is utilized, although for clar-
ity this would typically be the primary jack.
The secondary RJ45 jack can be used to
interconnect with another piece of networked
equipment. The management Ethernet port
will be used to access the management
webpages.

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If the Model 5401A’s Dante network is con-
figured for Switched ensure that only one
of the two Dante RJ45 jacks on the back
panel is connected to the LAN associated
with the Dante network. If both of the Model
5401A’s Dante RJ45 jacks are routed to
ports on the same LAN this will typically
“crash” the network! (Although some of the
latest/most-advanced Ethernet switches
will automatically detect and prevent such
a “network bridging” issue from occurring.)
If Switched+Mgmt is selected the same
issues as discussed in the previous two
paragraphs would again apply. The only
difference is that the management web-
pages would be accessed using the same
Dante Ethernet port that is being used to
access the Dante network. The manage-
ment Ethernet port will be disabled.
If Redundant is selected then Dante’s
Redundant networking capability will be
enabled. In this case, separate Ethernet
LAN connections should be made to the
Dante primary and Dante secondary RJ45
jacks. Again, the Model 5401A’s separate
management Ethernet port will be used to
access the management webpages.
If Redundant+Mgmt is selected in Dante
Controller then the network connection
made to the Dante primary Ethernet port
will also be used to access the manage-
ment web-pages. The Model 5401A’s sepa-
rate management port will be disabled.
IP Addresses
When a Model 5401A has been configured
for either the Switched or Switched+Mgmt
network mode a single Dante IP address
will be associated with the network connec-
tion that is made to either the Dante primary
or the Dante secondary RJ45 jack. If the
network configuration has been selected
for Redundant or Redundant+Mgmt then
separate IP addresses and related network
parameters will be assigned to the Dante
primary and Dante secondary Ethernet
ports. No matter what network mode has
been selected the Model 5401A will always
have a separate management IP address.
Typically, the Model 5401A’s Dante IP
address or addresses and related network
parameters will be determined automati-
cally using DHCP or, if that’s not available,
the link-local network protocol. If desired,
the Dante Controller application does allow
Dante IP addresses and related network
parameters to be manually set to a fixed
(static) configuration. While this is a more-
involved process than simply letting DHCP
or link-local “do their thing,” if fixed address-
ing is necessary then this capability is
available.
Note that if the Model 5401A’s network
configuration has been set for Redundant
or Redundant+Mgmt then the Dante prima-
ry and Dante secondary IP addresses and
related parameters can be independently
configured. This allows both Dante inter-
faces to be configured automatically, both
interfaces to be configured manually, or one
interface to be configured automatically and
the other to be configured manually.
By default, the Model 5401A’s management
IP address and related network parameters
will be determined automatically using
DHCP or link-local. A configuration option,
accessible using the front-panel display
and associated buttons or the management
webpages, allows manual control of the
management IP address, subnet mask, and
gateway address values.
AES67 Configuration –
AES67 Mode
Dante Controller allows a Model 5401A to
be configured for AES67 operation. This
requires the AES67 mode to be set for
Enabled. As previously noted in this guide,

Model 5401A User Guide Issue 2, July 2021
Studio Technologies, Inc. Page 15
if AES67 mode is enabled then PTPv2 will
be utilized and the Dante transmitter (out-
put) channels will use multicast. The sam-
ple rate will be fixed at 48 kHz.
Preferred Clock Source
By the very nature of its intended applica-
tion, the Model 5401A will normally serve
as the Leader Clock for all Dante-enabled
devices. The unit has the ability to com-
municate with the Dante network, selecting
itself as the Preferred Leader and causing
the Enabled Sync to External function to
be enabled. The status of these two pa-
rameters can be observed using the Clock
Status function in Dante Controller.
Settings accessible using the Model
5401A’s management webpages allow ex-
tensive changes to the clock configuration.
These are provided for use when trouble-
shooting or addressing special applications.
In most cases, the Model 5401A’s default
settings would be appropriate and should
be utilized.
Model 5401A
Configuration
Many Model 5401A Dante Leader Clock
operating parameters can be configured
using the management system’s webpages
that are provided by way of one of the unit’s
Ethernet ports. The specific port utilized for
management will depend on the network
configuration that is selected using the
Dante Controller application. A standard
web browser is all that is required to utilize
the menu webpages.
Several key network configuration param-
eters can also be viewed and revised using
the Model 5401A’s front-panel graphics dis-
play and associated pushbutton switches.
Refer to Appendix D for details on which
parameters can be revised in this manner.
Management IP Address
It’s easy to identify the Model 5401A’s man-
agement IP address by way of the front-
panel display. If the screen saver function
is active, as it will be in most situations,
one of the five pages that will automatically
display will show the current management
IP address. As such, a user can simply
observe the sequencing menu pages and
watch for the one that displays the cur-
rent management IP address. If it’s desired
that the current management IP address
be continuously displayed then the Enter
pushbutton switch on the front panel should
be pressed. This will stop the screen saver
function and cause the current manage-
ment IP address to display. It will also allow
the various menu pages to be accessed
using the up, down, left, and right pushbut-
ton switches. Simultaneously pressing the
left and right arrow buttons will cause the
screen saver mode to begin again. The
screen saver mode will also automatically
start two minutes after the last press of any
of the front-panel pushbutton switches.
How the management Ethernet port obtains
its IP address will depend on the manage-
ment interface configuration setting. The
default method is automatic so the Model
5401A’s management port will first try to
obtain an IP address using DHCP. If that
is not successful an IP address will be
assigned using the link-local protocol. An
address of 169.254.x.x will indicate that an
IPv4 address was established using link-lo-
cal. The Model 5401A may also have been
configured to use a manual (fixed or static)
IP address. The front-panel display and as-
sociated pushbuttons, or the Model 5401A’s
management webpages, can be used to re-
view and/or make changes to the manage-
ment IP address and related parameters.

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Accessing the Management
Webpages
To access the Model 5401A’s home web-
page, type the unit’s management IP ad-
dress into a browser’s search bar. (It’s
possible that some browsers may require
including the text http:// followed by the IP
address.) Of course, the computer associ-
ated with the browser must be on the same
LAN and subnet as the Model 5401A.
Home Menu
Once the Model 5401A menu system has
been accessed the Home webpage will ap-
pear. It provides six display-only fields along
with a link to the Login menu webpage. The
fields are similar to those provided in the
Main menu configuration webpage. The
current clock source field will display which
timing source is actively being utilized by
the Model 5401A. The Sync Input status
field displays the current operating condi-
tion of the sync input whose BNC jack is
located on the unit’s back panel. The four
Dante sync status fields will display the role
that the Model 5401A is actively playing as
PTPv1 and PTPv2 timing resources for the
devices connected to the associated net-
work or networks. Details about these fields
are provided in the Main menu paragraphs
found later in this section.
Login Menu
From the Home webpage click on the Login
tab to access the Login webpage. Entry of
a valid user name and password is required
to access the additional configuration
menus. The Model 5401A doesn’t incorpo-
rate a sophisticated security implementa-
tion. The User name and password, as well
as the underlying software, is intended to
keep “honest” people from making unau-
thorized changes to the configuration of the
Model 5401A. It is not intended as a sophis-
ticated, rigorous security system.
Should the applicable user name and/or
password be misplaced, refer to the Techni-
cal Notes section and/or Appendix H of this
guide for a recovery method.
User Name: Enter the Model 5401A’s user
name into this field. It is case sensitive.
The default user name is guest. If both the
default user name and the default password
are active then the user name will display in
this field.
Password: Enter the Model 5401A’s pass-
word into this field. It is case sensitive. The
default password is guest. If both the default
user name and the default password are
active then the password will display in this
field.
Log In Button: Click on the Log In button
to submit the entered user name and pass-
word. If the correct entries have been made
the Main menu webpage will display. If an
incorrect user name and/or password is
entered then a login failed message will be
displayed.
Main Menu
Once the correct user name and password
have been submitted the Main menu web-
page will be displayed. This menu provides
the ability to select three important operating
parameters as well as displaying seven key
real-time conditions. In addition, the menu
system allows direct access to other menu
webpages. Refer to Appendix E for a view of
the Main menu.
Main Clock Source: This is a configurable
field with three choices: Internal, Sync Input,
and Dante.
This setting determines which source will
be the main (normal) timing source that is
used by the Model 5401A’s circuitry as its
own “Leader” timing reference. This is the
clock source that will be used by the Model
5401A’s PTPv1 and PTPv2 servers that

Model 5401A User Guide Issue 2, July 2021
Studio Technologies, Inc. Page 17
are critical to the Model 5401A’s support
of related Dante devices. When Internal is
selected the Model 5401A’s temperature-sta-
bilized, high-performance crystal oscillator
is utilized. This will provide excellent timing
accuracy and consistent long-term perfor-
mance. This source is far superior to that
provided by other standard Dante devices.
This is the correct choice if a high-quality
reference signal is not going to be connected
to the sync input.
When Sync Input is selected the Model
5401A’s sync input function will be utilized.
Using a BNC jack, located on the Model
5401A’s back panel, an external source of
word clock, video reference, or 10 MHz sine
wave can be connected. Circuitry within the
Model 5401A will “lock” (synchronize) the
internal timing signals to the externally pro-
vided reference signal.
Selecting Dante will instruct the Model
5401A to use the clock signal provided by
its Dante interface circuitry as its reference
timing source. The Dante interface circuitry
will either use its internal crystal oscillator or
synchronize to another Dante device on the
associated network. The actual clock source
used by the Model 5401A’s Dante interface
will depend on a setting in the Dante Con-
troller application.
The Model 5401A includes the choice of
Dante as the main clock source only for trou-
ble-shooting or other factory-directed activi-
ties. It’s not expected that this selection will
ever be used during normal Model 5401A
operation. By selecting Dante the excellent
timing performance that can be provided by
the sync input or the internal oscillator would
not be utilized.
Failover Clock Source: This is a configu-
rable field with two choices: Internal and
Dante.
This configuration choice selects which tim-
ing source will be used should the Model
5401A’s selected main clock source be-
come unavailable. Specifically, the failover
source will be used if a valid sync source is
not connected to the sync input. If Internal
is selected then the unit’s crystal oscillator
will be utilized as the Leader clock source
should a valid sync input signal be unavail-
able. If Dante is selected then the failover
source will be the timing signal derived from
the Model 5401A’s Dante interface.
From a performance standpoint it’s prefer-
able to select Internal. This ensures that the
best clock performance can be obtained
should the failover condition be active.
However, selecting Dante would allow an
interesting, albeit obscure, alerting feature to
become active. In the Dante Controller ap-
plication, a device such as the Model 5401A
that has been selected as the Preferred
Leader with an external source allowed will
have an error condition occur if the Model
5401A’s Dante interface doesn’t detect an
external reference being applied. And los-
ing the external reference is what the Model
5401A’s circuitry will do should failover be
activated and Dante selected as the failover
source. In this way, a Dante network user
could be alerted to a clocking issue should
the Model 5401A lose its sync input source.
However, having an error condition reported
in the Dante Controller application is prob-
ably not terribly important. The Dante SYNC
LED, located on the Model 5401A’s front
panel, will also offer a clear indication of a
loss of an external sync input signal. This
LED will typically slowly flash green when
the Model 5401A is functioning correctly
as the Leader clock for the Dante network.
However, should the unit be configured to
use an external sync input signal and a valid
one is not present, the SYNC LED will flash
orange to indicate this loss of lock and that
the failover source is in use. In addition, the
display will provide a text indication of this
condition.

Issue 2, July 2021 Model 5401A User Guide
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Force Preferred Leader: This is a configu-
rable field with two choices: Disabled and
Enabled.
This function impacts how the Model 5401A
will control a Dante network’s selection
of which device is going to serve as the
Leader clock. As the main reason for the
Model 5401A’s existence is to serve as a
Leader clock, in most applications the unit
should be serving in that role. By forcing the
Model 5401A to be a Preferred Leader clock
it helps to ensure optimal Dante network
operation. By enabling this configuration,
users of the Dante Controller application
will not be able to accidentally disable the
Model 5401A as a Preferred Leader. One
can observe exactly what is meant by the
term Force Preferred Leader by unchecking
the Model 5401A’s Preferred Leader check
box in Dante Controller. After a short inter-
val the box will automatically return to the
enabled (checked) state.
How the Model 5401A handles forcing the
Dante network to be a Preferred Leader
clock and, if applicable, automatically sup-
porting an external clock input is not trivial.
This ability to control Dante network opera-
tion is part of the unit’s “secret sauce.” If the
Model 5401A’s clock source is configured
for Dante then the Model 5401A will force
off (uncheck) the Enable Sync to External
selection in Dante Controller. If the Model
5401A’s main clock source is configured for
Internal or Sync Input then the Model 5401A
will force on (check) the Enable Sync to
External configuration in Dante Controller.
This will apply as long as this specific Model
5401A is acting as Primary Leader, Leader,
or AES67 Leader.
Submit: A Submit button is located below
the Force Preferred Leader field. For any
changes made to the three configurable
fields on the Main menu webpage to be
saved and acted upon the Submit button
must be pressed.
Current Clock Source: This is a display-
only field with choices of Internal, Internal
(Failover Active), Sync Input, Dante, and
Dante (Failover Active).
The text Failover Active will display in red
as a warning of an abnormal condition that
warrants intervention. The current clock
source field can also display --- which in-
dicates a major hardware error and would
warrant contacting the factory.
When Internal is displayed it indicates that
the Model 5401A’s internal temperature-
stabilized oscillator is being used as its
timing reference. When Internal (Failover
Active) is displayed an abnormal condition
is occurring. In this case, the Model 5401A
has been configured to use an external
sync signal as the main clock source but
a valid one is not available; it is using its
internal temperature-stabilized oscillator as
the failover timing reference. If Sync Input
is displayed this indicates that an external
timing reference signal is connected to the
sync input BNC jack on the Model 5401A’s
back panel and it is being used as the main
clock source. If Dante is displayed this indi-
cates that the Model 5401A is using a timing
reference derived from its Dante network
interface. This is not an invalid condition but
would typically only occur in a troubleshoot-
ing situation. If Dante (Failover Active) is
displayed an abnormal condition is occur-
ring. In this case, the Model 5401A is using
a timing reference derived from its Dante
network interface. However, this is only oc-
curring because the configured main clock
source is not currently available.
Sync Input Status: This is a display-
only field with choices of Locked (Active),
Locked (Standby), Unlocked, and Idle. As
a warning of an abnormal condition the text
Unlocked will display in the color red.
If Locked (Active) is displayed this indicates
that a valid signal is connected to the Model

Model 5401A User Guide Issue 2, July 2021
Studio Technologies, Inc. Page 19
5401A’s sync input and is serving as the
unit’s timing reference. If Locked (Standby)
is displayed this indicates that a valid sig-
nal is connected to the Model 5401A’s sync
input and while it is capable of serving as
the unit’s main timing reference it is not cur-
rently serving as the main clock source.
If Unlocked is displayed it can be the re-
sult of several conditions. It can display if
a signal is connected to the Model 5401A’s
sync input but is not being recognized as
a valid timing reference. This can occur for
multiple reasons. The most common would
be due to a configuration mismatch, such as
if a video reference is connected while the
Model 5401A’s sync input is configured to
support a word clock source. It might also
indicate that a non-supported word clock
rate or an incompatible video reference is
connected. Unlocked could also be dis-
played if no signal is connected to the sync
input or if a connected signal is incorrectly
terminated, e.g., no termination applied
when one is required or if two terminations
(“a double termination”) were present.
Idle will display if the sync input has not
been selected as the Model 5401A’s main
clock source and a valid source has not
been connected to the sync input. It simply
indicates that the sync input circuitry is not
actively receiving an external signal.
Primary Leader Clock: A display-only field
will show the MAC (media access control)
address of the Dante network’s currently
active Primary Leader Clock. Displayed to
the right of the MAC address will be an ad-
ditional piece of information about what spe-
cific device is associated with the displayed
MAC address. If the MAC address is asso-
ciated with this specific Model 5401A then
the text will show (This Device). If the MAC
address is not for this specific Model 5401A
the text will show (Other Device).
A logical question to ask would be “so what
is this Other Device?” Unfortunately, the
Model 5401A’s firmware does not have
the ability to know more about a specific
Primary Leader Clock other than its MAC
address. It can only determine if the MAC
address matches this specific Model 5401A
or not. If the address doesn’t match then
another device has to be serving as the
Primary Leader. The Dante Controller may
provide more detailed information about a
Dante network’s clocking. And network soft-
ware or hardware tools may allow a MAC
address to be associated with a specific
device.
Note that the information provided in this
field can be a bit confusing, even to the
writer of this guide. But for a network maven
it can be very useful when troubleshooting
a complex network timing issue. Reviewing
several related issues to Primary Leader
Clock can be valuable. First of all, it’s impor-
tant to note that the reference to the word
primary in “Primary Leader Clock” has noth-
ing to do with the primary and secondary
Ethernet interfaces! In this context Primary
Leader Clock refers to the device that all
other devices in a Dante network will follow.
In most cases, a Model 5401A will serve
as the Primary Leader Clock. But there is
no requirement that it must play this role.
For example, a Model 5401A can serve as
a Leader Clock while following the timing
provided by another device that’s serving
as the Primary Leader Clock. For another
example, one Model 5401A could serve as
the Primary Leader Clock while several oth-
er Model 5401A units serve as PTP bound-
ary clocks. These boundary clocks would,
by way of a unicast PTP message, synchro-
nize with the Primary Leader Clock. The
boundary clocks could then provide PTPv1
and PTPv2 functionality (using multicast)
with timing based on that derived from the
Primary Leader Clock. This method may be

Issue 2, July 2021 Model 5401A User Guide
Page 20 Studio Technologies, Inc.
used to provide Dante device timing across
different subnets for complex or especially
large applications. For more in-depth control
of these clocking issues the Dante Domain
Manager (DDM) software application can be
very useful.
Dante Sync Status: The Model 5401A can
simultaneously serve as a Leader clock for
both Dante primary and Dante secondary
networks and is capable of supporting both
PTPv1 (IEEE 1588-2002) and PTPv2 (IEEE
1588-2008). As such the unit is capable of
acting as four independent Leader clocks:
PTPv1 for Dante primary, PTPv2 for Dante
primary, PTPv1 for Dante secondary, and
PTPv2 for Dante secondary. While the
PTP processes are asymmetrical, they do
share the same internal timing reference.
The Model 5401A can also act as a PTPv1
and PTPv2 clock follower but that would
typically be utilized only for test purposes.
Standard and Redundant Dante (no AES67
support) uses PTPv1 and that is always
enabled in the Model 5401A. AES67 utilizes
PTPv2 clocking and if support for AES67
is desired within the Dante environment it
must be enabled using a configuration set-
ting in the Dante Controller application.
The Model 5401A’s Main menu has four
fields that display the real-time sync sta-
tus of the PTPv1 and PTPv2 functions for
the Dante primary and Dante secondary
interfaces. If the network configuration in
Dante Controller for this specific Model
5401A has been selected for Switched or
Switched+Mgmt the clocking status of the
Dante primary interface will be displayed.
In this situation, the Dante primary PTPv1
interface will show Leader, Follower, Link
Down, or Error (with the latter showing in
red text). If AES67 support is enabled in
Dante Controller then the same choices
will also be displayed in the primary PTPv2
field. If AES67 support is not enabled then
Disabled will show in the primary PTPv2
field. Since Dante secondary is not enabled
then the secondary PTPv1 and secondary
PTPv2 fields will show Disabled.
If the Model 5401A’s network configura-
tion has been selected for Redundant or
Redundant+Mgmt then both the primary
PTPv1 and secondary PTPv1 sync sta-
tus fields will display their respective sync
status. They will show the same choices
as described above: Leader, Follower, Link
Down, or Error (with the latter showing in
red text). If AES67 support is enabled in
Dante Controller then the same choices will
also be displayed in the primary PTPv2 and
secondary PTPv2 fields. If AES67 support is
not enabled then Disabled will show in both
the primary PTPv2 and secondary PTPv2
fields.
Should Leader be displayed in a specific
field it would indicates that this specific
Model 5401A is acting as the Leader clock
for the Dante network and clock function
associated with that field. If Follower is dis-
played this indicates that this specific Model
5401A is obtaining its timing reference from
another Dante device on the network. This
would be the current display if this specific
Model 5401A was serving as a “hot” stand-
by Dante Leader clock.
If Link Down is displayed this will indicate
that a valid Ethernet connection has not
been made to the RJ45 jack associated with
that field’s Model 5401A’s Ethernet inter-
face. A display of Error would indicate that
this specific Model 5401A is having a per-
manent or temporary issue with its internal
circuitry. There may be occasions where
Error would display for a few seconds while
Model 5401A circuitry first becomes active.
Sync Input Menu
The Sync Input menu has parameters that
are related to the Model 5401A’s sync input.
This allows an external source of timing to