Controlling the xNode mixer with LWRP

Updated by Bryan Jones

Information on this protocol is provided without warranty or support of any kind. Telos Alliance provides no warranty express or implied as to the appropriateness of this document to your application. It's provided as a reference to use with other software that might have the capability to control Axia devices directly.  No direct support for this protocol is available.  If you are attempting to use this with your automation system, please contact your vendor.

Scope

This document is specific to the mixer in Telos Alliance xNodes. The xNode matrix mixer is available in versions 2.0 or higher of the following xNodes.

  • Analog xNode
  • AES/EBU xNode
  • Microphone xNode
  • Mixed Signal xNode
GPIO xNode and the xSelector xNode do not support the matrix mixer.

The xNode Matrix Mixer

The xNode Mixer consists of 24 mixers, each with the possibility of 24 (25 on the Mixed Signal) mix "points."

There are eight Livewire Mixes (mixer outputs), each with a left and right (16 mixes) and four physical outputs, each with a left and right (8 mixes) that make up the 24 mixes.

Likewise, there are eight Livewire mix "points," each with a left and right (16 points) and four physical inputs, each with a left and right (8 points) for a total of 24. On the Mixed Signal xNode, the Mic input is a 25th mix point.

Here's a screenshot of the mixer page to help explain. Note the Mixers across the top and the Points down the side.

The Protocol

Livewire Routing Protocol requires a telnet connection to the device on port 93. Note that all LWRP commands are in ALL CAPS.

The mixer protocol uses the MIX command where the format is MIX <CH> <POINT:gain>

Sending the MIX command returns the status off ALL mix points and subscribes you to any changes.

MIX

Returns the following

MIX 1 1:0 3:0 5:0
MIX 2 2:0 4:0 6:0
MIX 3 19:0
MIX 4 20:0
MIX 5 
MIX 6 
MIX 7 
MIX 8 
MIX 9 
MIX 10 
MIX 11 
MIX 12 
MIX 13 
MIX 14 
MIX 15 1:0
MIX 16 2:0
MIX 17 
MIX 18 
MIX 19 
MIX 20 
MIX 21 
MIX 22 
MIX 23 
MIX 24 

You can see that the MIX results match up with the screenshot shown above.

The text shows that MIX 1has Point 1 at 0db 1:0Point 3 at 0db 3:0 and Point 5 at 0db 5:0

MIX 2 had Point 2 at 0db 2:0 Point 4 at 0db 4:0 and Point 6 at 0db 6:0

If you follow the mixer page, you see that MIX 1 is the LEFT channel Output 1 and MIX 2 is the RIGHT channel of Output 1. Output 1 (Source 1) is labeled as AVMix

Controlling Mix Points

You must send the LOGIN (all caps) command in order to make Mix changes by LWRP. The syntax for Login is LOGIN <pass>. If your xNode has no password, then LOGIN and press enter.

Sample commands
MIX 1 7:0 
adds Point 7 (DST 4 LEFT) to MIX 1 (SRC 1 LEFT) at 0db

MIX 1 7
clears the previously made Mix Point

MIX 1 7:-30
adds Point 7 (DST 4 LEFT) to MIX 1 (SRC 1 LEFT) at -3db

You can send multiple points at once.

MIX 1 1 3 5 7 
clears all the privously made mix point for MIX 1

MIX 1 1:0 3:0 5:0
adds Points 1, 3, and 5 to MIX 1 (SRC 1 LEFT) at 0db
A real-world example

In the example above, we have three automation outputs being mixed together. Those three outputs become a new Livewire Source called AVMix. Let's assume we want our automation system to ADD the Fourth channel to the mix to turn on and off a Satellite audio feed. Automation would need to send the following;

MIX 1 7:0
MIX 2 8:0

You can see after sending those commands the mix points are now reflected on the Mixer page of the xNode

Sending the commands;

MIX 1 7
MIX 2 8

will remove the mix points.

Additional notes

You must send LOGIN every time you connect. You do not need to send LOGIN with every command, only when establishing the telnet connection.

If you want to SEE what the commands look like, make a telnet connection to port 93 and send the MIX command. This will subscribe you to changes. You can make changes to the Mixer page on the xNode and see the results in real-time in the telnet window. The opposite is also true. If you make changes via the telnet connection, the web page is updated in real-time.

Making a stereo route requires sending two commands; one for the Left mix point and one for the right.

When making a mono sum, you need to account for the gain increase that happens from summing manually. When summing, you should lower the gain by -3db. For example;

MIX 1 7:-30 8:-30
MIX 2 7:-30 8:-30

Creates a full mono sum of the input labeled SAT 1 INPUT

Sending just the command

MIX 1 7:0 8:0

puts the Left channel of our SAT 1 INPUT on both the left AND right channels of our AV Mix. Use this if your satellite channel is only left or right, but you need it on both channels of the mix.


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