The term 2-wire refers to an analog intercom system such as ASL, Clear-Com, RTS-TW, and Tecpro, where only one cable with two active conductors is used for an unbalanced duplex connection. This means that all connected devices will always listen and talk to all other devices simultaneously. 2-wire systems are easy to implement and install but also very limited in use. Furthermore, they are prone to suffer from external interference, causing inadequate or disrupted voice communications.
The term 4-wire refers to two pairs of (balanced) wires either sending or receiving audio, 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 matrix intercom channel.
A channel is considered active when the other side has its talk enabled but does not transmit any audio signals yet. The other side can be any user, either communicating via a group or directly in a private one-to-one conversation.
Tip: There is a differentiation between
An alert call is an extension of a call signal that draws more attention by flashing the status LEDs and channel screen. In addition, a configurable buzzer signal will alert users not wearing their headset.
An alert call is triggered by sending a standard call signal for more than two seconds.
The announcement channel is a special listen-only channel with a higher priority than regular channels. Using the default configuration, incoming audio on the announcement channel will attenuate all other normal channels. This can be helpful to ensure clear commando communication in hectic intercom systems.
The announcement channel always uses a group to transmit audio to a user. Each user can have an individual announcement channel configured.
The audio bandwidth is the difference between the highest and the lowest frequencies carried in an audio stream. The sample rate determines the maximum audio frequency that can be reproduced.
Theoretically, the maximum frequency that can be represented is half of the sample rate. The limit is a little lower in practice, so the practical upper-frequency limit for a sample rate of 32.000 Hz is a little over 15.000 Hz but below 16.000 Hz.
If so desired, a system can be set to either a 16 kHz or a 48 kHz sample rate, resulting in an audio bandwidth of respectively 7 kHz or 22 kHz. This can be done to reduce the network load or to increase the audio quality.
Headset Bias voltage¶
The bias voltage allows operating headsets using an electret microphone. If enabled in the user's audio profile, Green-GO supplies up to 2.5 V on the XLR4 headset connector.
There is a separate setting for the XLR3 microphone power should the device feature one.
The buzzer is an internal speaker in the Green-GO BPX belt packs and WBPX wireless belt packs that transmits an auditory alert call. On devices featuring a front speaker, the buzzer signal can be configured to be transmitted via the speaker.
The Call signal is a non-verbal communication request and can be sent directly to a user or group via a channel. A call sign is sent by briefly pressing the corresponding function button - a continued press of the button results in sending an alert call. Sending and receiving calls can be enabled for each channel individually.
The properties for a user can be empty. When a user with unset properties is loaded onto a device, it will adopt the properties as currently configured on the device.
A Channel is primarily an allocation of communication. The Green-GO Engine provides 32 regular channels and four special channels. Each regular channel can be assigned to any user or group and provide different modes of operation, depending on the configuration.
A compressor reduces the dynamic range of an audio input by attenuating the louder sections of the input signal, making signal clipping less likely.
The compressor in a Green-GO device is not fully parameterized.
The configuration file contains all relevant information about the entire Green-GO system. Devices needs to be a member the same configuration to be able to communicate. A Green-GO device can join other devices on the network by cloning their configuration file.
You can create a custom configuration file with the Green-GO Control software, granting total freedom to create custom users, groups, and routing.
The Green-GO Control software can either join an existing configuration on the network or adopt devices to its own configuration. Once adopted, devices will automatically acquire the config from the Green-GO Control software, and they will stay synced with the software as long as it is running.
Tip: A Green-GO config is Unique to its configuration ID. It is found in the config info card or the info menu of a device.
Config name and file name are not unique identifiers. All devices with a configuration file with the same configuration ID are members of the same config and will be able to communicate together.
A condenser microphone is based on a principle that is similar to a capacitor. The power required to operate a condenser microphone can be supplied to any XLR3 front mic connector by configuring the mic power setting.
Cue signals can be sent from the MCX rack, MCXD desktop, and WPX Wall Panel X stations to any user or group as a visual (light/popup) signal as well as an auditory signal. Cue signals in a Green-GO system can consist of three stages:
- First, an attention signal is sent to the receiver. The receiver may answer this signal.
Please check our quickstart guide on how to answer an incoming cue signal.
- Next, the attention signal changes to a hold/ready signal.
- Finally, a GO signal can be sent to the receiver.
How an attention signal is handled can be configured in the user's settings menu or card. Using the
Auto Answer option, the attention signal is skipped, making the light signal two-staged; hold/ready signal → GO.
DECT stands for Digital Enhanced Cordless Telecommunications - a communications standard developed by ETSI that is mainly known for being used in cordless telephone systems. Most countries have a license-free frequency range that can be used for DECT. The amount of carrier frequencies (1728 MHz spacing) available in each country differs. DECT uses both FDMA (Frequency-Division Multiple Access) and TDMA (Time-Division Multiple Access). Multiple frequencies are available, each with 24 time-slots. Each frequency carries 12 upstream and 12 downstream time slots.
The Green-GO WBPX wireless belt pack and WAA wireless antenna, by default, use a double-width time slot to get the audio quality to a 7 kHz audio bandwidth. It is, however, possible to reduce the audio bandwidth if more devices need to be connected.
Devices vs network items
- A BPX is both a device and a network item.
- A MCX is both a device and a network item.
- An Antenna is a network item but not a device.
- A Wireless belt pack is a device but not a network item.
- A Bride is both a device and network item.
- A remote BPX (connected through a bridge) is a device but not a network item.
DHCP (Dynamic Host Configuration Protocol) is the network protocol that automatically and dynamically assigns IP addresses to devices (hosts) on an IP network.
- A DHCP server needs to be active on a network to be able to hand out addresses
- The IP of a device needs to be set to Dynamic to be able to obtain an IP address from the DHCP server
The direct channel is a special channel for ad-hoc communication. It allows user
A to talk to user
B even though user
B does not have user
A on a channel. User
B will receive the audio and is able to use the Answer/Reply function to talk back to user
A. The Reply function is available during the active time after communication has stopped.
- Jack has Mary assigned to a regular channel.
- Mary has Jack not assigned to a regular channel.
- Jack talks to Mary.
- Jack will be temporarily assigned to the Direct channel of Mary.
- Mary will be able to talk back to Jack by using the Reply function.
The Dim function allows for specific audio sources to be attenuated according to their channel priority. Specifically, certain audio sources can be given a higher priority to suppress any other sources when these high-priority sources are active.
There are six distinct priorities - three fixed priorities and three assignable priorities. The following table shows the priorities from highest to lowest.
|Priority||Channels||Attenuation of lower channels|
|AN||Announcement channel||Priority Dim|
|HIGH||CH 1 - 32 + Direct||Priority Dim|
|MED||CH 1 - 32 + Direct||Priority Dim|
|LOW||CH 1 - 32 + Direct||Priority Dim|
|PGM||Program channel||Program Dim|
When audio is received on the emergency channel, all other audio received will be muted.
Audio on the announcement channel will attenuate all regular channels by the amount set in the Priority Dim setting.
The three assignable priorities can be used to set up an attenuation scheme for the regular channels. The Priority Dim setting will be used as the attenuation for the lower priority channels.
The program audio channel has the lowest priority and has an independently set Dim amount.
Dynamic IP addressing does not set a fixed IP address for a device. If a DHCP server is present, an IP address is assigned by the server. If a DHCP server is not present, devices automatically get a self-assigned IP. In both cases, the subnet mask is set automatically.
The default setting for a Green-GO device is dynamic. In practice, this means that in a local island network, no IP setup is needed, and the network side can be treated as zero-config.
The Emergency Channel is a special listen-only channel. Any group can be assigned to this channel. The emergency channel has the highest priority of all channels, meaning that incoming audio on the emergency channel will mute all other channels.
Warning: Be careful when granting users access to the groups assigned to an emergency channel, as accidental audio in this group will block communication on the receiving devices.
Consider using the security settings to prevent users from potentially assigning the emergency channel's group to one of their channels.
An electret microphone is a type of electrostatic capacitor-based microphone. Electret microphones are commonly used in headsets due to their small size, low weight, and relatively low cost. An electret microphone requires a small bias voltage to operate.
There are 32 regular channels available to every Green-GO user device or interface port that is in user mode. Not all of the channels are always visible on the device's user interface. The channels that are not visible on the user interface are referred to as Extended Channels. For example, on a BPX in 4 channel UI mode, only the first four channels are visible. Channels 5 to 32 are the extended channels in this case. Audio received on these channels is mixed into the output of the device. As long as an extended channel is active, the Answer/Reply function can be used to talk back on this channel.
A flex list is a list of up to 20 channel assignments consisting of users and/or groups. Each user or device has one flex list. Users or devices can have one or multiple channel modes set to flex. Such a channel can be re-assigned quickly by instantiating the flex list popup, which allows scrolling to the available flex list. Selecting an item in the list with a click of the Encoder will assign this item to the channel and allows you to start a conversation with that user or group.
While only one instance of a flex list is present on a user or device, multiple channels can be in flex mode. Every channel configured with the
Flex mode is controlled and switched individually.
Instantiate the flex list popup
Starting a device in
Boot Mode might be necessary. E.g., to clear the memory or to repair a firmware error. The basic procedure is the same for all types of devices, whereas the button use varies depending on the device.
To start a device in Forced Boot Mode, press the boot button while providing power to the device. Release the button after 1-2 seconds. The display will now display
Green-GO Boot x.x (forced).
|Devices with a black rotary encoder||Press the Rotary encoder while powering on the device.|
|Beltpack X shaped devices||Press the bottom right button whilst powering on the device.|
|Devices without User interface||Press the red button on the bottom of the device while powering on the device.|
Clearing the memory of a device is recommended after a firmware update. A memory clear is executed by performing the following steps:
- Start the device in forced boot mode.
- Release the button.
- Press the boot button again for 30 seconds - till the timer hits 0.
- Release the button.
- After a couple of seconds, turn the device off and back on to return to the normal operation mode.
If corrupted firmware or failure occurs during a firmware update, the display will report a
To resolve this, perform the following steps:
The gain determines the amplification of an audio source. A positive gain will boost the signal, and a negative gain will attenuate the signal. A gain of 0 dB is called unity and will put audio through on a 1:1 ratio.
The gate threshold is a level set in the gate that will cause all incoming audio registering below this level to be cut off. Setting a gate threshold can be a useful tool for cutting off background noise (when microphones are kept open accidentally) and for setting up interfaces for VOX activation.
The longer the gate hold time, the longer a channel will remain active once audio has gone back below the configured threshold. Setting the hold time too long may introduce unwanted background noise and setting it too short may abruptly cut the end off of a user's speech.
The Green-GO Engine is the abstract designation for the audio matrix of a Green-GO device or port. The Green-GO Engine is identical on all devices, containing the 32 regular channels and special channels. A config file and a user need to be loaded onto the Green-GO Engine in order to set up communication.
User interface and input/output options differ from device to device.
The General Purpose In- and Outputs are used to interface with third-party equipment. GPIOs are present on the following devices:
- MCX rack station
- MCXD desktop station
- Audio InterfaceX
- Q4WR quad 4-Wire interface
- WP Wall Panel
- MCD desktop station
- MCR rack station
Inputs can trigger events on the Green-GO Engine, like enabling a talk on a specific channel or sending a cue. Outputs are triggered by events on the Green-GO Engine, like an active channel or a received call. See the full properties and electronic specifications of GPIO's. A GPIO port features a D-Sub 9 connector with two inputs and two outputs.
GPIO control is a communication signal that can be used to silently trigger GPIO implementations connected to any device on the local network. This gives more flexibility when configuring a GPIO implementation as there is no need to use regular user communication as a trigger.
A user's channel can be configured to exclusively send the GPIO Control signal with the press of a Button and act as a dedicated trigger.
Green-GO groups are similar to the concepts of a conference, ring or party line - every member can talk and listen simultaneously. For a user to become a group member, the group needs to be assigned to one of the user's 32 regular channels. There is no limit to the number of members in a group, with a maximum number of 400 groups supported in a single Green-GO configuration.
All host devices on a network need an address to be able to connect to each other, combined with a netmask that determines the segmentation of the network. An Ip address always consists of two parts, a (sub)net address and a host address. The size of both parts is determined with the netmask.
Tip: If you are not familiar with IP addresses and or IT-type networks, out of the box, Green-GO uses dynamic addressing by default. This means that all devices are capable of configuring themselves as part of an unmanaged standalone network.
An IPv4 address is 32 bits in size, resulting in a total of 4.294.967.296 theoretically possible unique addresses. For readability, each 8-bit block is represented by its decimal equivalent - resulting in a XXX.XXX.XXX.XXX form where each block of 8-bits an octet has a value of 0 to 255. Not all addresses are freely available, and only specific address ranges are reserved for multicast and private networks. The highest address of a subnet is always reserved for broadcast transmission.
Example IP addresses
The netmask determines which part of the IP address is the sub(net) address and which part is the host address.
The basic netmasks are:
| || |
| || |
| || |
A binary position with a
1 sets that part of the address to the net. A
0 sets that part of the address to the host.
IP subnet examples
The IP/netmask combination ...
... will enable the following:
192.168.1.201are able to communicate on subnet 192.168.1
- They can not communicate with
192.168.4.102- who is on subnet 192.168.4
10.21.5.21are able to communicate on subnet 10.21
Note that - in this example - communicate means that the devices are able to send each other IP messages, not engage in actual voice communication.
Hosts that are not in the same subnet can be routed to be able to send messages back and forth. When a host can not find the destination host in its subnet, it will send the message to the gateway address that is set. Setting the gateway is not needed when devices are in the same subnet and don't need to send messages outside of their subnet.
IP based intercom system¶
The Green-GO IP-based communication system enables complex communication structures. Users can communicate in groups or with each other directly. The system is unique in that there is NO central processing unit. All the routing and mixing of the audio signals is done in the devices themselves.
Advantages of the Green-GO IP based intercom system:
- Easy to deploy and integrate.
- Extremely flexible.
- No single point of failure; a single Green-GO device can never take down the entire system.
- Linear cost from 2 to 3000 users.
The isolate function can temporarily mute all other channels when one or more talk(s) are activated. Individual channels can be excluded from the isolate function by setting the listen mode to
The isolate function can be useful in situations where a lot of channels are active simultaneously. Utilizing the Isolate function will cut off all channels except for the ones that have the talk function enabled. The
Isolate Ignore option can be used to keep important channels un-muted.
A latch is a button behavior mode for the Talk function of a channel. When the Talk Mode is set to Latch, the channel will toggle the talk state between
talk active and
not active. The amount of time the button is pressed for is not a factor. If the channel is
not active, the state will be toggled as soon as the button is pressed (falling edge). When the channel is in the
talk active state, the state will be toggled again when the button is released (rising edge).
When the talk mode is set to Latch/Momentary, the button has a dual function. Shortly pressing the button will toggle the talk state. Pressing longer will trigger the Momentary button behavior.
The level determines the amplification of an audio signal. Channels and outputs have a level in dB where a positive level will boost the signal, and a negative level will attenuate the signal. A level of 0 dB is called unity and will let the audio through with a 1:1 ratio.
Line In/Out refers to a simple audio input and output; an input directs all incoming audio to a single group, an output sends out all audio present on a single group. Devices like the MCX rack station have an extra Green-GO Engine operating only with line in/out functionality. The Green-GO Engines of an interface like an Audio InterfaceX or Q4WR quad 4-Wire interface++ can be configured to operate in
Line In/Out mode instead of the fully-featured user mode.
Listen on talk¶
Listen on Talk function temporarily un-mutes a muted channel when the channel state changes to
Talk Active. This is especially useful for users that only occasionally participate in communication on a channel. As soon as the channel state reverts to
Not Active, the channel is muted again.
By default, all channels have the listen mode set to
Listen on Talk. The
Listen on Talk mode can be disabled by setting the listen mode of a channel to
Listen on Talk Ignore or
Green-GO devices have a separate, permanent memory where local changes are stored. All changes made on a device are stored in this memory but not in the config file. Reloading a user on a device will sync the user settings back to the device. Changes made to things like the channel assignments or user settings can be synced to the user using the Green-GO Control software.
Changes on a device¶
Changes on a device can be made in 2 ways:
- Using the device's user interface.
- Changing a property in the device view of the Green-GO Control software.
Matrix-based intercom system¶
A matrix-based communication system enables complex communication structures. Users can communicate in groups or directly with each other. All audio signals are normally routed to the central processing device. Mixed audio signals are then routed back to the outputs.
Downsides of a matrix-based intercom system can be:
- Configuration and installation of a matrix-based communication system usually take great effort.
- The central unit can be a single point of failure.
- High initial cost and non-linear scaling of costs.
Tip: There is a separate setting for the XLR4 bias voltage.
Momentary is a button behavior mode for the talk function of a channel. When the talk mode is set to momentary, the channel state changes from 'not active' to 'talk active' as long as the button is pressed.
When the talk mode is set to
Latch/Momentary, the button has a dual function. Pressing the button once will latch the talk state. Pressing longer will trigger the momentary button behavior.
Communication in a Green-GO system is done through UDP port
5810 on a multicast group. Each configuration should use a unique multicast address or group to communicate on the local network. Usually, the multicast address is generated at the creation time of the configuration file based on the configuration ID.
Warning: Some property changes will trigger a new config ID - and, therefore, a new multicast address!
Please be cautious while changing the following settings:
- Config Password
- Admin Password
If the local IT infrastructure calls for a fixed multicast address, the multicast address can be fixed by manually assigning it in the configuration settings.
A network item is a physical Green-GO device with a network interface to connect to the local Green-GO network. Not all Green-GO devices are necessarily a Network item.
Devices vs network items
- A BPX is both a Device and a Network item
- A MCX is both a Device and a Network item
- An Antenna is a Network item but not a Device
- A Wireless belt pack is a Device but not a Network item
- A Bride is both a device and network item
- A remote BPX (connected through a bridge) is a Device but not a network item
NO-NC stands for
normally open and
normally closed and defines the default state of a GPIO.
normally openinput is triggered when the contact is closed.
The input is triggered when the switch is closed.
normally openoutput is non-conductive in the idle state and becomes conductive when the output is triggered.
The switch is closed when the output is active.
normally closedinput is triggered if the contact is opened.
The input is triggered if the switch is opened.
normally closedoutput does conduct in the idle state and stops conducting if the output is triggered.
The switch is open when the output is active.
PoE / Power over Ethernet¶
Devices in the Green-GO system are powered by Power over Ethernet, a system that supplies both IP data and power through a single network cable. The standard used by the Green-GO system is IEEE 803.2af (supporting both, mode A and mode B). Rack-mounted devices and multi-channel stations have a separate 12V DC input allowing for an optional non-PoE power input that can also serve as a redundant power supply.
Popups can be displayed when cues, calls, direct communication, or signals from extended channels are received. A colored popup with a text message indicating the origin and type of signal will be displayed on the screen. The types of popups that are displayed can be configured with the popup mode setting.
Normal channels and special channels have a specific priority. By appointing a priority to a channel, less critical (lower priority), sources can be attenuated - depending on the configuration of the
DIM setting - when the channel is active.
The program audio channel can be used to add a stage sound feed into the output mix on a device. The source for the Program Audio channel must always be a group. Multiple program groups can exist in a Green-GO system. Any line in/out can be utilized as a source for the program group. In addition, users with access to the program group on a channel can talk to the program channel.
Push to talk (PTT)¶
Push To Talk functionality originates from the 2-way (half-duplex) radios that require a button to be pressed to enable audio transmission. In a Green-GO system, the momentary button behavior mode mimics a 2-way radio's PTT functionality.
With the RDX radio interface, a relay contact emulates the button press on the radio.
The sample rate describes the number of audio samples carried per second, expressed in (k)Hz. The default sample rate is 32 kHz and applies to the entire Green-GO system. In the configuration settings, the sample rate setting determines the audio bandwidth, which determines the audio quality.
When a device network is set to dynamic, but no DHCP server is present on the network, the device will receive a self-assigned link-local address. This is a randomly generated address in the 169.254.0.0/16 range with a netmask of 255.255.0.0. Green-GO devices will retain their self-assigned address as long as no other device is using it.
Sidetone sets the amount of own audio fed back into the output. This enables users to monitor their own (microphone) input and serve as confidence feedback to check if the microphone is actually open.
There are four special channels, each with its own specific purpose:
The Answer/Reply function allows to directly answer to incoming voice communications without the need to look at the device to see which channel is active. This function can also be used to reply to extended- or direct channels. The answer mode can be set in the reply mode setting.
Users or devices can have a room assigned to them. Once a device is a member of a room, audio from this same room can be attenuated with the
Room Dim property. E.g., this can be useful in a control room with multiple user stations using a speaker to prevent echoes or feedback.
To start a conversation on a channel, the microphone needs to be enabled. This is done by pressing the talk button, thus switching the channel to the talk active state. Each channel's talk button can be set to momentary or latch.
You are a user! Every intercom participant or integration is a user. The complete set of features of the Green-GO Engine is only available to users.
The users can be created with the help of the Green-GO Control software. When a user is linked to a device, all configured settings will be loaded onto the device. Device-specific configurations can be stored with device profiles inside a user's configuration.
A VLAN - or Virtual Local Area Network - is a virtually separated network area for networks of the third layer in the OSI model. A VLAN is normally configured for each port individually on all layer-2 network switches used. Communication between individual VLANs is normally not possible without a router. Suppose further protocols are carried through the network infrastructure. In that case, it is recommended to isolate the network traffic of a Green-GO system from the rest of the network communication using a VLAN. Isolating the network traffic prevents unexpected network behavior.
Green-GO can work across multiple routed VLANs, but it is generally advised to use a BridgeX interface for these applications to buffer for jitter and reduce the risk of broken or bad audio on your intercom solution.
VOX - or Voice Operated eXchange - is an automatic voice-operated switch that acts as an automatic PTT. The advantage of a VOX switch is that it enables hands-free (automatic) operation, while the main drawback is that high background levels can lead to unwanted triggering of the switch.