Studio Technologies 5421 User manual

Copyright © 2020 by Studio Technologies, Inc., all rights reserved
www.studio-tech.com
User Guide
Issue 1, March 2020
This User Guide is applicable for serial numbers
M5421-00151 and later with main firmware version 1.00 and later
and STcontroller application version 2.06.00 and later.
50671-0320 Issue 1
Model 5421
Dante® Intercom Audio Engine

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Model 5421 User Guide Issue 1, March 2020
Studio Technologies, Inc. Page 3
Table of Contents
Revision History ........................................................... 4
Introduction .................................................................... 5
Getting Started .............................................................. 7
Dante Configuration ...................................................... 9
Model 5421 Configuration ............................................. 11
Operation ...................................................................... 13
Technical Notes ............................................................ 14
Specifications ............................................................... 18
Appendix A ................................................................... 19
Appendix B ................................................................... 20
Appendix C ................................................................... 21

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Revision History
Issue 1, March 2020:
• Initial release of complete document.

Model 5421 User Guide Issue 1, March 2020
Studio Technologies, Inc. Page 5
Introduction
The Model 5421 Dante® Intercom Audio
Engine is a high-performance, cost-effective,
flexible solution for creating party-line (PL)
intercom circuits. It’s directly compatible with
the Studio Technologies’ range of 1-, 2-, and
4-channel Dante-enabled beltpacks and other
interface-related products. The unit is suitable
for use in fixed and mobile broadcast facili-
ties, post-production studios, commercial and
educational theater environments, and enter-
tainment applications.
Only a Gigabit Ethernet network connection
with Power-over-Ethernet (PoE) support is
required for the Model 5421 to provide a
powerful resource in a variety of Dante appli-
cations. Front- and back-panel LEDs provide
operating status indications. The Studio Tech-
nologies’ STcontroller software application
allows personnel to view and configure key
operating parameters. The unit’s lightweight
“1/2-rack” enclosure can be used stand-alone
or mounted in one space (1U) of a standard
19-inch rack enclosure with an optional rack-
mount installation kit. To meet the latest in-
teroperability standard the Model 5421’s Dante
implementation meets the requirements of
AES67 as well as supporting the Dante Do-
main Manager (DDM) application. Using DDM,
compliance with ST 2110-30 may be possible.
The Model 5421 provides one 16-channel
audio engine which can be configured to pro-
vide from one to four “virtual” intercom circuits.
The term “audio engine” was selected to de-
scribe a set of audio input, processing, routing,
and output resources that can be configured to
support specific intercom requirements. Unlike
general-purpose Dante digital matrix devices,
the Model 5421 is optimized to allow direct
support for theater, small broadcast, and
general intercom applications.
Configuration and Functionality
Using the STcontroller software application a
configuration choice selects how the Model
5421’s 16-channel audio engine is segmented.
The allows efficient use of the Dante channels
to support the needs of specific applications.
As all Dante intercom beltpacks are essentially
Figure 1. Model 5421 Dante Intercom Audio Engine “throw down” front view
Figure 2. Model 5421 Dante Intercom Audio Engine back view

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4-wire devices (having independent receiver
(input) and transmitter (output) channels)
“virtual” (simulated) party-line functional-
ity must be created within the Model 5421’s
digital processing resources. This requires that
the maximum number of participants (users)
on any one “party-line” be defined and an
appropriate configuration be made.
The 16 channels offered by the Model 5421
are configured into what are called groups.
Simple configuration choices are accessed
using the STcontroller software application
and allow the number of groups and their
sizes to be selected. Group configuration can
range from one group having 16 channels (a
complete audio engine being used for a single
group) to four groups each having four chan-
nels. The size of a group will dictate how many
devices and associated users can be part of
any one party-line. Five choices allow a range
of group configurations to be selected with the
default setting being two 8-channel groups.
Using the Dante Controller application, each
group can be assigned a unique name. These
names would typically reflect how each spe-
cific group is going to be utilized. Names such
as Production, Lighting, Stage Manager, or
Follow Spot would be typically used in theater-
oriented intercom applications.
Technically, each group supports party-line
operation by creating a series of unique “mix-
minus” outputs, one for each channel in the
group. These specialized outputs allow each
intercom user assigned to that specific group
(a “party-line”) to hear all members of that
group except for themselves. (Thus comes
the term “mix-minus” or a mix of all source
but themselves.) By each user receiving a
mix-minus signal precise control of each
user’s local sidetone audio level and overall
audio quality can be maintained.
Applications
The Model 5421 is compatible with many
Dante-compliant devices including the extensive
range of intercom beltpacks from Studio Tech-
nologies. These include the single-channel/
dual-listen Model 372A and Model 373A, the
2-channel Model 370A and Model 371A, and
the 4-channel Model 374A. The Model 5421
will also function directly with other Dante-sup-
porting devices such as the Model 348 Intercom
Station and Model 391 Dante Alerting Unit. In
addition, the Model 5421 can function with matrix
intercom systems, audio consoles, and wireless
intercom base stations.
Dante Audio-over-Ethernet
Audio data associated with the Model 5421 is
sent and received using the Dante audio-over-
Ethernet media networking technology. Audio
signals with a sample rate of 48 kHz and a bit
depth of up to 16, 24, and 32 are supported. Up
to 16 Dante receiver (input) and 16 transmitter
(output) channels are available to implement
virtual party-line (PL) intercom circuits.
AES67 and DDM
Using the Dante Controller software application,
the Model 5421’s Dante interface can be con-
figured to support, or not support, AES67 digital
audio signals. The unit is also compliant with the
Dante Domain Manager (DDM) software appli-
cation. DDM offers an enhanced set of network
control and monitoring features, making it ideal
for security-conscious applications. This may
also allow the Model 5421’s audio channels to
support ST 2110-30.
Pro Audio Quality and Auto Mix
The Model 5421’s audio circuitry was designed
to meet the demands of professional audio ap-
plications, far exceeding that of “typical” intercom
products. Audio processing is performed in the
digital domain using a high-speed field-program-
mable-gate-array (FPGA) integrated circuit.

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The Model 5421’s Auto Mix function utilizes a
sophisticated FPGA-based algorithm to provide
enhanced audio intelligibility. This feature is
unique to party-line (PL) intercom applications
and offers the opportunity for users to obtain
the absolutely finest audio performance.
Status LEDs and Configuration
Two LEDs, located on the Model 5421’s front
panel, provide an indication of the Dante inter-
face’s status. LEDs associated with the back-
panel R45 jack display the real-time status of
the connected Ethernet signal. No pushbutton
or configuration switches are provided. The
Studio Technologies’ STcontroller software
application is used to configure the unit’s
operating parameters.
Ethernet Data and Power Source
The Model 5421 interconnects with a local-
area-network (LAN) using a standard Gigabit
(1000 Mb/s) twisted-pair Ethernet signal. The
physical connection is made by way of a RJ45
receptacle. The Model 5421’s operating power
is provided by a Power-over-Ethernet (PoE)-
compliant Ethernet signal. For network man-
agement purposes the unit’s Ethernet interface
will report to the power sourcing equipment
(PSE) that it’s a class 2 (low power) powered
device (PD).
Simple Installation
The Model 5421 is housed in a rugged, light-
weight aluminum enclosure that is designed to
be “field tough.” It can be used as a standalone
portable unit, supporting what’s known in the
broadcast world as “throw-down” applications.
Or it also can be directly placed upon on a
rack-shelf or other flat surface. Optional rack-
mount installation kits are available to allow
one or two units to be mounted in one space
(1U) of a standard 19-inch rack enclosure. As
previously mentioned, the Model 5421 uses
a standard RJ45 connector to allow fast and
convenient interconnection. Initial operation
will commence when a Gigabit Ethernet signal
with Power-over-Ethernet (PoE) capability is
connected. Normal operation will take place
after the unit “boots up.” This process requires
approximately 30 seconds.
Future Capabilities and Firmware
Updating
The Model 5421 was designed so that its per-
formance and capabilities can be enhanced
in the future. A USB type A connector, acces-
sible on the unit’s back panel, allows the main
firmware (embedded software) to be updated
using a standard USB flash drive. To imple-
ment its Dante interface the Model 5421 uses
Audinate’s Broadway™ integrated circuit. The
firmware in this integrated circuit can be up-
dated via the unit’s Ethernet interface, helping
to ensure that the Dante performance remains
up to date.
Getting Started
In this section a location will be selected for
the Model 5421 Dante Intercom Engine. A
Gigabit Ethernet (GigE or GbE) connection
that supports Power-over-Ethernet (PoE) will
be made using a standard RJ45 patch cable.
If desired, an optional rack-mount installation
kit will be used to mount one or two Model
5421 units into a standard equipment rack.
System Components
Included in the shipping carton are a Model
5421 Dante Intercom Audio Engine and a
printed copy of this guide. If one or two Model
5421 units are going to be mounted in a 19-
inch equipment rack then an optional rack-
mount installation kit is required. Specific kits
are available for rack-mounting one or two
Model 5421 units. If a rack-mount installation
kit was purchased it would typically have been
shipped in a separate carton.

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Locating the Model 5421
The location of the Model 5421 will primarily
depend on being within the 100-meter (325-
foot) twisted pair Ethernet cable limitation. But
the overall length limit can be overcome by
using a fiber-optic interconnection between
the Model 5421-related Ethernet switch and
another Ethernet switch that’s part of the ap-
plication’s local-area-network (LAN). With fiber
interconnects there’s no reason why a Dante-
supported LAN can’t be distributed over many
miles or kilometers.
Protecting the Enclosure
The Model 5421 is shipped as a self-contained
unit suitable for portable use or placement in a
semi-permanent location. Installed on the bot-
tom of the chassis are screw-on “bump on”
protectors (also known as rubber “feet”). These
are useful if the unit is going to be placed on
surfaces where scratching of either the Model
5421’s enclosure or the surface material could
take place. However, if applicable the “feet”
can be removed without the use of a tool, when
rack- or custom-mounting the unit.
Making an Ethernet Connection
The Model 5421 has one RJ45 jack which is
located on the unit’s back panel. It requires
connection with a Gigabit Ethernet (GigE or
GbE) signal that also supports Power-over-
Ethernet (PoE). This is typically provided by
a port on a standard PoE-enabled Gigabit
Ethernet switch. The required Gigabit Ethernet
signal must follow the 1000BASE-T standard
and meet the requirements of IEEE® 802.3af
for PoE. To support power management func-
tionality on the associated PoE switch (PSE)
the Model 5421 enumerates itself as a PoE
class 2 (low power) powered device (PD).
The Model 5421’s Ethernet interface supports
auto MDI/MDI-X and, as such, using a cross-
over or “reversing” cable is not required. And
while “Fast Ethernet” (100BASE-TX or 100 Mb)
may also function correctly, it’s not recom-
mended for maximum reliability.
Rack Mounting
For some applications it might be desirable to
mount one or two Model 5421 units into one
space (1U) of a 19-inch rack enclosure. Rack-
mount installation kits, purchased separately,
are available from Studio Technologies. The
following sections provide details on how to
use the rack-mount kits. Refer to Appendices B
and C of this guide for graphical descriptions of
how to attach the rack-mount kits.
Rack-Mounting One Model 5421 Unit
Rack-mount installation kit RMBK-11 is used
to allow rack mounting of one Model 5421 unit.
The kit contains one standard rack bracket,
one long rack bracket, and four 6-32 thread-
pitch Phillips-head machine screws. Refer to
Appendix B for a visual explanation.
Begin the installation by removing the four
“bump on” protectors from the bottom of the
Model 5421’s chassis. They can be removed
using one’s fingers to rotate them counter-
clockwise; no tool is required. It’s probably a
good idea to store the four “bump on” protec-
tors for possible later use.
With assistance from a #2 Phillips-tip screw
driver, use the machine screws to attach the
standard and long rack brackets to the sides
of the Model 5421’s enclosure. The screws will
mate with the threaded fasteners that can be
seen on the sides of the Model 5421’s enclo-
sure, near the front of the unit.
Mount the standard rack bracket to the left
side of the Model 5421 (when viewed from the
front) if the unit needs to be located on the left
side of the rack enclosure. Then mount the
long rack bracket to the right side of the Model
5421. Mount the brackets in the opposite
orientation should the Model 5421 need to be
located on the right side of the rack enclosure.

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Once the “bump on” protectors have been re-
moved and the standard and long rack brack-
ets have been installed the Model 5421 will
be ready to be mounted into the designated
equipment rack. One space (1U or 1.75 verti-
cal inches) in a standard 19-inch equipment
rack is required. Secure the unit into the equip-
ment rack using two mounting screws per side.
Rack-Mounting Two Model 5421 Units
Rack-mount installation kit RMBK-12 is used
to allow one-space (1U) rack mounting of two
Model 5421 units. The kit can also be used to
mount one Model 5421 and another product
that is compatible with the RMBK-12 (such as
the Studio Technologies’ Model 48D Dante
Bridge). The kit contains two standard rack
brackets, two joiner plates, eight 6-32 thread-
pitch Phillips-head machine screws, and two
2-56 thread-pitch Torx T7 thread-forming ma-
chine screws. Refer to Appendix C for a visual
explanation.
Begin installing the kit by removing the four
“bump on” protectors from the bottom of each
chassis. They can be removed using one’s fin-
gers to rotate them counterclockwise; no tool
is required. Store the eight “bump on” protec-
tors for possible later use.
With assistance from a #2 Phillips-tip screw
driver, use two of the 6-32 machine screws to
attach one of the standard rack brackets to the
left side (when viewed from the front) of one
of the Model 5421 units. The screws will mate
with the threaded fasteners that can be seen
on the sides of the Model 5421’s enclosure,
near the front of the unit. Using two more of
the 6-32 machine screws, attach one of the
joiner plates to the right side of that same
Model 5421 unit.
Again using two of the 6-32 machine screws,
attach the second standard rack bracket to
the right side of the second Model 5421 or
other compatible unit. Using the final two 6-32
machine screws, attach the second joiner plate
to the left side of the second Model 5421 or
other compatible unit with an orientation of
180 degrees from the way in which the first
plate was installed.
To complete the assembly, “join” the units
together by sliding each joiner plate through
the other. The grooves in each joiner plate will
carefully align with each other and form a rela-
tively tight bond. Line up the two units so that
the front panels form a common plane. With
the aid of a Torx T7 driver, use the two 2-56
machine screws to secure the two joiner plates
together. The screws should fit snugly into the
small openings formed by the mating of the
two joiner plates.
Once the “bump on” protectors are removed
and the 2-unit assembly is created it is ready
to be mounted into the designated equipment
rack. One space (1U or 1.75 vertical inches) in
a standard 19-inch equipment rack is required.
Secure the assembly into the equipment rack
using two mounting screws per side.
Dante Configuration
For audio to correctly pass to and from the
Model 5421 requires that, at a minimum, sev-
eral Dante-related parameters be configured.
These configuration settings will be stored in
non-volatile memory within the Model 5421’s
circuitry. Configuration will typically be done
with the Dante Controller software application
which is available for download free of charge
at www.audinate.com. Versions of Dante Con-
troller are available to support Windows and
OS X® operating systems. The Model 5421
uses the Broadway integrated circuit to imple-
ment the Dante functionality. The Model 5421
is compatible with the Dante Domain Manager
(DDM) software application. This may allow
ST 2110-30 routes to be established to and
from the Model 5421’s audio channels.

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Unit and Channel Names
The Model 5421 has a default Dante device
name of ST-M5421- along with a unique suffix.
The suffix identifies the specific Model 5421
that is being configured. The suffix’s actual
alpha and/or numeric characters relate to the
MAC address of the unit’s Broadway integrated
circuit. By default, the 16 Dante receiver (Rx)
and 16 Dante transmitter (Tx) audio channels
are organized as two 8-channel groups. The
channel default names are A01-Group A
through A08-Group A and B01-Group B
through B08-Group B. Using the Dante Con-
troller application, the default device name and
channel names can be revised as appropriate
for the specific application.
Sample Rate, Encoding, Clocking,
& Latency
The Model 5421 only supports an audio
sample rate of 48 kHz with no pull-up/pull-
down values available. Encoding choices are
PCM 24, PCM 16, and PCM 32, but in virtually
all cases the default selection of PCM 24 would
be appropriate. This is due to the processing
within the Model 5421 being performed in
24-bit. Device Latency can be adjusted if
required but the default value of 1.0 msec
will typically be correct.
Network Configuration –
Addresses
By default, the Model 5421’s Dante IP address
and related network parameters will be deter-
mined automatically using the DHCP protocol
or, if not available as a network resource, the
link-local protocol. If desired, Dante Controller
allows the Model 5421’s IP address 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 addressing is
necessary then this capability is available. But
in this case, it’s highly recommended that a
unit be physically marked, e.g., directly using a
permanent marker and “console tape,” noting
its specific static IP address. If knowledge of a
Model 5421’s IP address has been misplaced
there is no reset button or other simple method
to identify and restore the unit to a default IP
setting. Refer to the Technical Notes section of
this guide for additional details.
AES67 Configuration – AES67 Mode
Using Dante Controller, the Model 5421 can be
configured for AES67 operation. This requires
that the AES67 Mode configuration choice to
be set for Enabled. By default, the Model 5421
has this mode configured for Disabled.
Clocking
As is the case for all Dante devices, the Model
5421 can serve as a leader clock for a Dante
network. But in many cases, the unit will re-
ceive “sync” from another device that’s been
selected as the “primary leader” for the ap-
plication. As such, the check box for Preferred
Leader associated with the Model 5421 would
typically not be enabled. But for supporting a
small to medium sized set of Dante devices
there’s no reason why the Model 5421 couldn’t
perform admirably as a leader clock. In this
case checking the box for Preferred Leader
would be appropriate.
Audio Routing
Each Model 5421 Dante transmitter (Tx) out-
put channel associated with a channel in an
intercom group must be routed (subscribed) to
the desired receiver channel on an associated
piece of equipment. The receiver (Rx) input
associated with the same channel in the same
intercom group must also be routed (sub-
scribed) to that same piece of equipment. One
transmitter channel and one receiver channel
always create a transmitter/receiver pair that is
used as one channel in a party-line (PL) group.