[ Closed ] Using Advanced CobraNet in the NIONs

We get a lot of questions about how and why to use Advanced CobraNet in the NIONs.

It should be noted that Advanced CobraNet is also available in all CAB devices except the CAB 4n with CM-1 (The CAB 4n with CM-2 does support Advanced CobraNet without a problem).

So what is Advanced CobraNet?
Advanced CobraNet allows the designer to leverage the full flexibility of CobraNet. You are NOT locked into 8 channel audio bundles as some other manufacturers would have you believe. Some of this can be seen through the use of the CAB 4n where 4 channel audio bundles are used to communicate to the four 4 channel card slots. However, it is even more flexible than that because you can have anywhere from 1-8 channels in a bundle and a NION will support the use of up to 24 bundles simultaneously. (An astute observer may notice that there are actually 16 bundle transmitters and 16 bundle receivers in the NION, however you may only use up to 24 of them in any combination at a given time.)

So, what does this really mean and why does it matter to me?
Well, are you using CobraNet connected amplifiers with 2, 4, and 8 channels all in the same system? What about the new MediaMatrix nWall 2.0 CobraNet Connected Wall Plate? Also, using different combinations of MediaMatrix CAB devices and CobraNet devices from other manufacturers can all be combined into a single comprehensive system and various devices all require different handling of how the subchannel mapping is laid out.

We are going to work through a simple example using a NION, a CAB 4n with two input and two output cards, and a CAB 16o. It is assumed that you have a good working knowledge of how the network needs to be configured to support CobraNet and are reasonably familiar with the CobraNet Programmer's Reference Manual. If this is not the case, please click on the link and get yourself a copy and read through it. It is immensely helpful in hammering out all the little details about how and why CobraNet works to provide us a stable and reliable communication transport across an Ethernet network. It is further assumed that you have started an NWare project file and have a NION, a CAB 4n with input cards in slots A & B and output cards in slots C & D, and a CAB 16o.

The first step is to go into the Device Properties for the NION and enable Advanced CobraNet. On the "Audio Network Configuration" select the option that says "CobraNet CM1: Advanced" as shown in attachment #1 below: 1. SelectAdvancedCobraNet.jpg After this is complete, deploy the project to the NION.

attachment #1:

After the project has been deployed, you may now start configuring the CobraNet. I prefer to set up the CAB devices first. Open the CAB 4n object and in the green box enter the Device ID number that is displayed on the front panel of the hardware. (for information about how to set the hardware ID of the CAB 4n, please see "Setting the Hardware ID" section of the CAB 4n Hardware Manual.) Then open the CAB 16o device and set the hardware ID of that unit. (The hardware ID of the CAB 16o is set by some rotary switches under the removable panel on the front of the CAB 16o. If you have already done the CAB 4n, you will be familiar with how this works.) Please see attachment #2 below.

attachment #2:

Once the Hardware ID's have been configured in the CAB's we can go through the CABs and assign the bundle numbers. You should have a scheme for bundle numbering figured out before you just start sticking numbers in willy-nilly. Hopefully you went ahead and read through the CobraNet Programmer's Reference Manual as was recommended above. If not, you NEED to do that now so you know what bundle numbers you should be using. Please see attachment #3 below: 3. SetBundlesInCABs.jpg at this time. Note that the CAB 4n has FOUR separate pages. One for each card. Each page requires a unique bundle number for each 4 channel bundle that is attached to each card.

attachment #3:

After setting up the bundles in the CAB's, we can now move to the CM-1 page in the NION device to configure the other end of the links. Please see attachment #4 below: 4. NIONAdvancedCobraNetOrientation.jpg at this time for an orientation to the Advanced CobraNet page in the NION. The Violet column on the left is where the bundle number goes. You may note that at the top is the transmitting section and the bottom is the receiving section. There are 16 transmitters and 16 receivers in the NION. The gray indicators to the left of the bundle number field will switch to green when the bundle is connected. The green field in the middle is where the actual bundle subchannel is mapped to a flyoff in NWare. This is where the actual audio channel assignment takes place.

attachment #4:

So, moving forward with entering the bundle numbers and subchannel mapping, please see attachment #5 5. ConfigureBundlesforCAB4n.jpg. As you can see here, the bundles for the two output cards have been entered into transmitters 1 & 2 respectively, and the subchannel mapping is 1-4 and 5-8 for them respectively. The numbers that go into the green fields correspond directly with the flyoffs in NWare to identify precisely which channel is going where. One important detail about configuring the transmitters for the CAB 4n is the 4 channel bundles. By default the salmon colored "Num Chan" column is filled with 8's. This means that the bundle will ALWAYS transmit 8 channels of audio regardless if there is an actual subchannel assigned to it or not. This can be extremely wasteful to our available bandwidth. In the case of the CAB 4n transmitters, these 8's should be changed to 4's as demonstrated in the image below. Configuring the receive bundles is very similar to configuring the transmitting bundles; just plug in the bundle number and the flyoff numbers into the appropriate fields.

attachment #5:

Next we will configure the two 8 channel bundles to transmit audio to the CAB 16o. Please see attachment #6: 6. ConfigureCAB16oBundles.jpg. This is as simple as entering the bundle numbers and flyoff numbers into the bundle and subchannel fields respectively. You may note that the 3rd transmitter is bundle number 1003 and subchannel #1 starts with flyoff #9. This is because we already used flyoffs 1-8 for the CAB 4n in transmitters 1 and 2. So we need to use flyoffs 9-16 in bundle transmitter #3 and 17-24 in bundle transmitter #4. In this case we are transmitting 24 discrete channels of audio. Each channel is a unique mix.

attachment #6:

We are now complete with configuring the CobraNet at this point. As long as the bundle indicators are all green, the CobraNet is connected and transmitting. However, a couple comments should be made about how the audio actually shows up in the NWare user interface. To that end, please see attachment #7 below: 7. FlyoffsInNWare.jpg.

attachment #7:

In this image you can see the flyoffs that say "NION #1.CM-1.in.#" and "NION #1.CM-1.out.#". The numbers that show up at the end of these flyoffs correspond to the numbers that we plugged into the green grid in the NION device's CM-1 page. The Yellow and Purple flyoffs were color coded to keep it simple in identifying which flyoffs are connected to what. These yellow and purple flyoffs will be used in the next image. They are there to give friendly names to the hard coded CobraNet I/O flyoffs that are automatically generated when you create the NION.

Once we have the audio in the NION, all manner of audio processing can be done to it. In attachment #8 below: 8. SystemSchematic.jpg, shows a very simple schematic with the sources from the CAB 4n on the input side of the mixer and the outputs from both the CAB 4n and the CAB 16o on the output side of the mixer. With this simple matrix mixer, you can mix any or all of the input channels in any relationship to each of the outputs individually. This would yield a highly flexible system. Obviously a system would normally include some additional processing for the inputs, depending on what they are doing; and for the outputs, depending on where they are going.

attachment #8:

In all, Advanced CobraNet offers extreme flexibility when working with CobraNet and it is one of those advanced topics that has been in NWare since the beginning. Hopefully this post has helped clear up some of the mystery that surrounds CobraNet. CobraNet is not that complicated. Too often people try to make it more difficult than it really is.

Have fun out there!