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Last update: September 14, 2022

The Audio InterfaceX

Attention: the Interface X does not support 48 kHz configs on firmware 5.0.1.

InterfaceX Front View

The INTX Audio Interface X is a dual port 4-Wire and single port 2-Wire device, used for integrating not only line level audio signals, in and out of the system but additionally a channel of 2-wire. Featuring a full-color TFT or LCD display that shows information about channels, cue signals; configurable by a multifunction encoder, with access to many of the same functions and features as most other Green-GO devices.

Connectivity to 4-wire systems is achieved via 2x XLR3F and 2x XLR3M with Connectivity to 2-wire systems is achieved via a single XLR4F. Powered via PoE through the network cable connected to the devices Ethercon port or 12V DC connector (power supply not included).

The term 4-wire refers to two pairs of (balanced) wires, providing independent, bidirectional audio lines. They can act as a general-purpose line in/out device suitable for show relay and announcements or for linking to an external intercom channel.

The audio line setup is not an automated process. After the 2-wire system is established, an auto null should be undertaken to balance the audio between the two systems. Typically presenting as a single group, this connection also benefits from additional Green-GO features such as program audio and announce functions.

What's in the box?

The Green-GO audio InterfaceX comes with the following package contents:

  • 1 x Green-GO audio InterfaceX
  • 1 x Printed quickstart guide
Optional Green-GO accessories
  • Green-GO PoE network switches

Device overview

Front panel

InterfaceX Front Overview 1 Color TFT display

1 Multifunction encoder

Back panel

InterfaceX Front Overview
1 12V DC barrel connector
The 12V DC barrel connector serves as the secondary power input and can be used with an optional power supply.
1 2-Port 10/100 Mbps Neutrik EtherCON Switch
A 2-port 10/100 Mbps network switch with Neutrik EtherCON connectors. The first network port LAN 1 accepts PoE (IEEE 802.3af) and is the primary power input for the device.
2 D-Sub 9 GPIO connector
Two GPIO D-Sub9 connector each serve two in- and outputs for external control interfacing. Each GPIO port is directly linked to one 4-wire Green-GO Engine port.
2 4-Wire Ports
A Neutrik XLR3-Female Line-Input and A Neutrik XLR3-Male Line-Output for each port . The balanced XLR3 male line-input connector allows injecting analog audio signals into the Green-GO system. The balanced XLR3 female line-output connector allows extracting analog audio signals from the Green-GO system. Audio signals from and to the port are processed dependant on the 4 wire port mode.
1 2-Wire line terminator
Toggle switch to correctly terminate a un-used 2 wire port. When no 2 wire system is connected the line should be terminated: Switch is ON(in). When a 2 wire system is connected to the port the port should NOT be terminated: Switch is OFF(out).
1 2-Wire port
A Neutrik XLR3-Female 2 wire port to interface with analog 2 wire party-line systems.

The user interface

The user interface features one color TFT display and one multifunction Encoder.

InterfaceX UI Overview

The main screen features an overview of the device's Green-GO Engines with their current in- and output levels and (last) active channels. The top of the screen features the device's name and general network status.

A red X in the top right corner of the screen indicates no online configuration members found.

The 4-wire Green-GO Engine

The Green-GO Audio InterfaceX features two independendent 4-wire Green-GO Engines with a XLR3 line-input and -output that can be used to either integrate an alaog 4-wire intercom channel or a normal audio signal.

Each engine can be operated in two different modes:

Line In/Out
This is mode is very easy to configure but lacks many features of the Green-GO Engine like GPIO or call signal integration.
User Mode
The user mode enables all features of the Green-GO Engine. Using this mode, each engine will have access to one D-Sub 9 GPIO port to interface with external systems.

Line In/Out mode

The Line In/Out mode can be used to import external audio to a group or export a group to the line output. To enable the mode, the setting User has to be configured to the option Line In/Out. Afterwards, the available menu options will change.

Line Input

The line-input allows for transmitting audio through a group to other users in the system. A simple use case for the analog audio line-input on the back of the device would be external analog program audio that needs to be transmitted to multiple users in the system without the need for a dedicated audio interface.

The audio settings and destination (group) of the audio signal can be configured in the device settings.

Setup Menu Guide
Setup Menu
└──> 4-Wire Port 1|2
    └──> Line In
        ├──> Assign # (1)!
        ├──> Gain # (2)!
        ├──> Compressor # (3)!
        ├──> Gate Threshold # (4)!
        └──> Gate Hold # (5)!
  1. Defines the target (group) of the input.
  2. Defines the input gain of the signal.
  3. Configure a compressor on the input signal.
  4. Configure a noise gate on the input signal.
  5. Configure the gate hold timings.
Configure the line-input
Set the destination

To use the line-input to import an external audio source into the Green-GO system, we need to assign a Group that transmits the audio signal.

Setup Menu Guide
Setup Menu
└──> 4-Wire Port 1|2
    └──> Line In
        ├──> Assign: # (1)!
        └──> ...
  1. Assigns a group to the line-input.
Level the input signal

Input Signal Leveling

Next, the input signal should be leveled to a peak value around the 0dB mark using the VU-meter on the right side of the line-in setup menu.

It is highly recommended to disable the Gate Threshold and the Compressor during this process to achieve the best results.

Setup Menu Guide
Setup Menu
└──> 4-Wire Port 1|2
    └──> Line In
        ├──> ...
        ├──> Gain # (1)!
        ├──> Compressor: Off # (2)!
        ├──> Gate Threshold: Off # (3)!
        └──> ...
  1. Defines the input gain of the signal.
  2. Disable the compressor when leveling the input signal.
  3. Disable the noise gate when leveling the input signal.
Compressor and gate

The Compressor can be enabled if the dynamic input signal range is too high and the signal clips regularly.

The Gate Threshold acts as a noise-gate and can be activated to avoid transmitting background noise. Adjust this setting carefully to avoid blocking voice communication.

Setup Menu Guide
Setup Menu
└──> 4-Wire Port 1|2
    └──> Line In
        ├──> ...
        ├──> Compressor # (1)!
        └──> ...
  1. Configure a compressor on the input signal.
Setup Menu
└──> 4-Wire Port 1|2
    └──> Line In
        ├──> ...
        ├──> Gate Threshold # (1)!
        └──> Gate Hold # (2)!
  1. Configure a noise gate on the input signal.
  2. Configure the gate hold timings.

Line output

The line output allows to output the communications of a group to an external receiver. A simple use case could be an announcement channel that needs to be transmitted via external speakers to a larger audience.

In addition, the line output can be used to connect a more powerful active speaker as the user's output.

Setup Menu Guide
Setup Menu
└──> 4-Wire Port 1|2
    └──> Line Out
        ├──> Assign # (1)!
        ├──> Level # (2)!
        ├──> Limiter # (3)!
        └──> Loopback # (4)!
  1. Defines the source (group) for the line-output.
  2. Configure the signal level for the line-output.
  3. Configure a limiter for the output signal.
  4. Route the signal of the line-input to the line-output.

Configure the line-output

The configuration for the line-output can be done in the Device setup menu.

Set the source

We need to Assign a group to route its communications to the line-output.

Additionally, we can route the signal of the line-input to the line-output using the Loopback setting.

Setup Menu Guide
Setup Menu
└──> 4-Wire Port 1|2
    └──> Line Out
        ├──> Assign # (1)!
        ├──> ...
        └──> Loopback # (2)!
  1. Defines the source (group) for the line-output.
  2. Route the signal of the line-input to the line-output.
Level the output signal

Input Signal Leveling

Next, the output signal needs to be leveled to a peak value around the 0dB mark using the VU-meter on the right side of the line-out setup menu..

It is highly recommended to disable the Limiter during this process to achieve the best results.

Setup Menu Guide
Setup Menu
└──> 4-Wire Port 1|2
    └──> Line Out
        ├──> ...
        ├──> Level # (1)!
        ├──> Limiter: Off # (2)!
        └──> ...
  1. Configure the signal level for the line-output.
  2. Disable the limiter while leveling the output signal.

User mode

GPIO integrations

Attention: The D-Sub 9 GPIO integrations are only available when using the User mode.

The rear panel GPIO connectors enable external switches to initiate commands on the linked Green-GO Engine and also allows the device to set off external switch-controlled events using conditions such as active, talk, call, cue, etc.

The D-Sub 9 GPIO connectors each feature two inputs and two outputs with the following pin-outs:

GPIO Pin-Out Each D-Sub 9 GPIO connector is directly linked to one Green-GO Engine and its associated user.

GPIO Schematics Pin 1 offers 5 Volts of power with a maximum output current of 200mA.

Pins 6 and 7 offer common general-purpose ground.

General purpose inputs

Using the general-purpose inputs, it is possible to trigger local commands on the users Green-GO Engine. Allowing for external control over the users' channels and communication.

General Purpose Input The inputs can be set to either Normally Open or Normally Closed. If set to Normally Open, the configured function will be executed whenever the switch is closed. If set to Normally Closed, the configured function will be executed whenever the switch is open.

The inputs actuate with contact to the ground, with a max. +5V open voltage.

Setup Menu Guide
Setup Menu
└──> Device
    └──> GPIO
        └──> Input 1/2
            ├──> Function # (1)!
            ├──> Channel # (2)!
            ├──> Normaly # (3)!
            └──> Status # (4)!
  1. Defines the function that is triggered with the GPIO input.
  2. Defines the target/channel for the function.
  3. Defines if the input is normally open or closed.
  4. Lists the current state of the configured input.
Available input functions
Talk
Opens a defined channel for outgoing voice communications. This function will actuate for as long as the contacts are not in the normal state (momentary).
Call
Allows sending a call signal to a defined channel. This function will actuate for as long as the contacts are not in the normal state (momentary).
Cue Acknowledge
Allows replying to an incomming attention cue signal on any or on a defined channel with an acknowledment, setting the cue signal to ready. This function will trigger with the first pulse on the input (toggle).
Cue Abort
Allows aborting any outgoing cue signal on any or a defined channel. This function will trigger with the first pulse on the input (toggle).
Cue Attention
Allows to send an attention cue signal to a defined channel. This function will trigger with the first pulse on the input (toggle).
Cue GO
Allows to sent a direct GO cue signal to a defined channel. This function will trigger with the first pulse on the input (toggle).
Cue Clear
Allows clearing an outgoing GO cue signal on any or a defined channel. This function will trigger with the first pulse on the input (toggle).
Mic Kill

Acts as a remote switch to kill any active microphone on a defined channel (single user or all users in a group). This function will trigger with the first pulse on the input (toggle).

Warning: Configure this carefully as it will interrupt ongoing user communication.

GPIO Control
Sends a GPIO Control signal on a defined channel to trigger a remote GPIO integration.
Answer/Reply

Answers incoming communication on any or a defined channel. This function will actuate for as long as the contacts are not in the normal state (momentary).

Tip: Depending on the setting Reply Mode this function either answers the last incomming voice communication or all ongoing voice communications.

Cough Mute
Mutes the currently active user input. This function will actuate for as long as the contacts are not in the normal state (momentary).

General purpose outputs

Using the general-purpose outputs, it is possible to trigger and control external devices or relays with a set of functions and or states. Allowing to extend the control outside of the Green-GO network.

General Purpose Output The general-purpose output is a floating optocoupler. When activated, it's capable of passing 5mA with a maximum of 50 Volts. It can be used to switch third-party logic inputs directly, a signal-led, or with some extra circuitry drive bigger loads like relays.

As with the inputs, the outputs can be set to either Normally Open or Normally Closed, controlling the configuration's idle state.

Setup Menu Guide
Setup Menu
└──> Device
    └──> GPIO
        └──> Output
            ├──> Function # (1)!
            ├──> Channel # (2)!
            ├──> Normaly # (3)!
            └──> Test # (4)!
  1. Defines the function that triggers the output.
  2. Defines the source/channel for the function.
  3. Defines if the output is normally open or closed.
  4. Allows testing the configuration manually.
Available output functions
Channel Active

Activates as soon as any or one defined channel has the state active but isn't yet transmitting. The output actuates for the duration of this state (momentary).

Tip: Be aware that this function is influenced by the user setting Active Time. A channel will stay active for the configured duration after no signal is received.

Channel Vox

Activates as soon as any or one defined channel of the user receives active voice communication. The output actuates for the duration of this state (momentary).

Tip: Be aware that this function is influenced by the user setting Active Time. A channel will stay active for the configured duration after no signal is received.

Talk Enabled
Activates as soon as any or one defined channel of the user is manually opened to transmit voice communication. The output actuates for the duration of this state (momentary).
Call
Activates as soon as any or one defined channel receives a call signal. The output actuates once as soon as the state changes (toggle).
Alert Call
Activates as soon as any or one defined channel receives an alert call signal. The output actuates once as soon as the state changes (toggle).
GPIO Control
Activates as soon as any or one defined channel receives an GPIO Control signal. The output actuates once as soon as the state changes (toggle).
Driving an LED

Driving An LED

A signal LED can be driven directly with one GPIO output, utilizing pin 1 as a 5 Volt power supply.

A series of resistors must be added to the circuit to limit the current to a maximum of 5mA. The resistor needed depends on the LED used.

Your circuit for this application could look like the schematics to the left.

Driving a relay

Driving An LED

A simple circuit with a transistor is needed to drive an external relay with a current higher than 5mA through a GPIO output.

The schematics to the right can be used as an example.

Warning: Please be aware that the resistor between the power supply and pin 4 or 5 is dependent on the voltage of the power supply used!

The 2-wire Green-GO Engine

The setup menu

Technical specifications

General

Audio inputs

Line input

Audio outputs

Line output

GPIO

General purpose inputs

General purpose outputs

2-Wire line

Downloads

Firmware

Other


Written by: Chad Phelps, Henk-Jan Blok, Timo Toups