Wheatstone Audio Transport
Modern
router based systems have one thing in common – they all replace audio
trunk wiring with the ubiquitous CAT-5 or CAT-6 cable. Multiple audio
signals are transmitted via CAT-5, and in some case fiber, in
topologies that connect various system components like I/O frames and
control surfaces.
The exact methodology varies from one manufacturer to another. Systems
that use TDM (Time Domain Multiplexed) connections are available in
both ring and hub and spoke configurations. One system uses AoIP (Audio
over IP) for all of its interconnections.
Wheatstone has chosen to create what we call a composite system, using
a TDM hub and spoke architecture to link system components, combined
with AoIP portals for applications that are best served by that
approach.
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 click image to enlarge
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Advantages of the Composite Approach:
TDM architecture is well suited for moving audio between router frames.
There is very little data overhead, as the data stream does not need
the additional header information required for Ethernet based
packetized audio. As a result each link has greater capacity (128 audio
signals plus control data). There is virtually no latency (<2ms)
from any system input to any system output. This also simplifies the
system configuration, as each source and destination does not require
an IP address. We like to think of our links as “lean and mean” (and
fast , robust, and efficient).
The hub and spoke approach means that individual I/O frames can be
easily added or removed without upsetting the apple cart. As shown in
the system layout above right, individual frames simply plug into network
ports, whether they be on our Wheatnet high capacity audio switch or on
a network card equipped Bridge Router frame.
Need more than 128 signals
between frames? Just add another link.Need redundancy? Add a second Wheatnet with a complete set of failover links.
AoIP is clearly a very efficient way to move audio in and out of a
computer (i.e your automation servers and production machines). It is
also a good way to distribute an audio feed (like your off air monitor)
to various destinations on a LAN, like your PDs or GMs office. And AoIP
is certainly a developing technology.
New applications such as long distance transport using codecs and public Ethernet will become more widespread.
To capitalize on these existing and soon to arrive applications
Wheatstone provides our ET-2001 card (ET-Ethernet Transport). This card
installs in our Bridge Router frame and provides 16 input and 16 output
streams in RTP (Real Time Protocol) format. With the Wheatstone wdm
driver installed, up to 8 channels of audio can be sent to/from a
single PC using its NIC (Network Interface Card). A single network
connection replaces the soundcard and associated audio wiring, greatly
simplifying installation. Machine commands (Start/Stop commands, etc)
are also carried by this same connection. Typically the ET-2001 card is
interfaced through a standard 100baseT Ethernet switch, allowing
multiple servers to be connected.
While we’re on the topic of Ethernet connections, we should mention
that we use Ethernet to interface all of our extensive family of
harware control panels. This means that XY controllers, mic remote
control panels, and programmable button arrays are all connected to the
system using Ethernet. No complicated RS-485 wiring to work out. Our
controllers are IP addressable and can be connected through standard
hubs and switches.
We also use Ethernet to provide external control from third party
systems. Our control protocol is available to any vendor wishing to
control our system. The major radio automation vendors and a TV
newsroom automation manufacturer have already taken advantage of this
capability.
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Composite System Components
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Wheatnet Audio Network Switch
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Control Surfaces
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Bridge Router
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Satellite Router
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X-Y Router Control
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Other Components:
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Administrative PC, used for set up and maintenance
100 Base T Ethernet Switch
Programmable Panel with IP Interface
Automation Server with AoIP Connection
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Wheatstone
Advantage
“Lean and Mean” TDM interface for system component interconnection
Simplified configuration without complicated IP addressing issues
AoIP (Audio over IP) capability for Audio Server interface and future applications
Ethernet control for simplified interface to hardware controllers and third party systems
A composite system that uses the best of the available technologies!
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Distributed Intelligence
Manufacturing
Our modern 52,000 square foot
manufacturing facility is equipped with the latest technology and
tooling. From Lasers & CNC routers for cutting complex stainless
steel & wood parts to a complete surface mount line, all of which
enable Wheatstone to continue to lead the industry with innovative
designs and quality equipment.
 Learn more about Wheatstone Manufacturing
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