Dialogbox 4/2, User manual – Attero Tech DialogBox User Manual

Page 20

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DialogBox 4/2

User Manual

Attero Tech LLC 2013

Page A-2

614-00011-04

The modes are as follows:

o

Unicast – Used for one-to-one connections. In this mode, only one receiver at a time can receive this bundle.
Once a link is established from this transmitted bundle to a receiver, any future requests for that bundle from
other potential receivers will fail.

o

Multicast – Used for one-to-many connections. This mode broadcasts its contents over the entire network.
There is no restriction on the number of receivers. However, the downside is that CobraNet packets are
distributed to all nodes on the network, whether they need them or not thus creating possible network
bandwidth issues.

o

Multi-unicasts – Another one-to-many mode. Whilst this is the most efficient method for getting a bundle to
multiple receivers in terms of network bandwidth, it requires more processing power on the CobraNet device
so in this mode there is a maximum limit of four receiver connections (this can be reduced if required). If
more connections are required than the limit, the node can be configured to automatically switches to
multicast.


*Note:

When a bundle must be transmitted to multiple receivers, multi-unicast transmissions should be used where

possible.

Once the mode is selected, to enable a device to transmit the bundle, simply allocate the particular transmitter bundle a
non-zero number. Since this number identifies all the network packets sent out by that transmitter, each transmit
bundle number must be unique on a network2.


Now that the transmitter is set up, it is time to set up the receivers. In order to receive bundles, each CobraNet device
has up to eight bundle receivers. To enable a device to receive a bundle, simply allocate one of that device’s bundle
receivers the same bundle number as a transmitted bundle. By doing so, a virtual link is created and audio should now
be passed from one device to the other. It should be noted that no knowledge of a device’s network topology or
connection is thus required in order to configure audio connections. The only restriction to this is that a device cannot
be set up to receive a bundle it is also transmitting.

The above case creates a simple, one-to-one, unidirectional link. If more devices are required to receive that bundle,
allocate the same transmitted bundle number to a bundle receiver on the other CobraNet devices.

It is also important to note that CobraNet supports simultaneous bidirectional audio distribution in each device. Not
only could audio be sent from Device A to Device B but at the same time, should it be needed, audio could also be sent
from Device B to Device A. The exact bundle and routing configuration will be determined by the needs of each
individual installation. An installation may have multiple units transmitting multiple bundles. The only restriction is the
bandwidth available on the network to transfer the audio.

CobraNet does more than just transfer audio data. It can be used to pass serial information as well. A feature called
serial bridging has been incorporated that allows the passage of serial data between nodes. Each node can pass serial
data to a specific node or multicast the data to multiple nodes. A node can also receive data from either a single source
or multiple sources. Baud rates, data bits, stop bits, parity, and so on are all configurable. There is also support for
multi-drop serial buses as well.

Finally, CobraNet has the capability to alter all of the above options in real time making the whole system completely
dynamic. By use of control software, all of the bundle assignment parameters can be configured with no need to
change cables, switch out connectors, or pull new wiring. Most importantly, this control capability can be implemented
from a single location!

2

Bundle numbers range from 1 through 65535. A value of 0 represents an inactive bundle. Numbers 1-255 are

reserved for multicast mode transmissions only.

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