Green-GO is a cost-effective, multi-award winning, digital intercom over Ethernet, that uses a unique design concept to create complex communication systems suitable for major live events, multi-function performance venues, churches, high-end rental facilities and broadcasters. It is also suitable for building simple, expandable, systems for projects with less stringent technical requirements or tighter budgets. With this system, Green-Go have produced the first affordable way to enter the world of digital intercoms, with its many benefits.
The system is designed to operate on any 100Mbit Ethernet network without interfering with other data protocols co-existing on the system and will perform seamlessly, even when data traffic-levels are high. For network cabling, standard RJ45 connectors may be used, or for greater reliability, the more robust Neutrik etherCON connectors. System components that are not powered by their own external PSU, are driven by DC voltage derived from 'Power over Ethernet' (PoE). Audio quality is high, and, being digital, will not deteriorate over distance. Sampling rate is 16kHz with 16-bit dynamic range. System latency is low at only 12 milliseconds, so no lip-sync problems!
Green-GO differs fundamentally from other current intercom designs which use a central matrix or routing-engine at their core. Instead, each outstation holds all routing data, system set-up and user preferences. Operating without a central matrix eliminates the possibility of a catastrophic single component failure. In the event of a problem, a faulty device can be easily removed and its replacement can clone all system configurations from a neighbouring device on introduction to the network.
Terminology - Circuits, channels, groups and rings
Different terms are used, by the various manufacturers of intercom systems, to describe similar configurations. In this description, a 'channel' is used to describe a collection of user stations linked together by wire or wirelessly to allow users to communicate with each other. This is the same as a group, ring or circuit when used in the same sense.
A basic system can consist of just two beltpacks and, if Power over Ethernet(PoE) is not available locally, a PoE switch from almost any manufacturer. The intercom system can be expanded to provide up to 250 intercom channels and a total of 3000 individual users.
Six system components are currently available; beltpacks, wallmount stations, multi-channel desktop stations (8, 16, 24 and 32 channels), a 12-channel 19 inch rackmounting station, a Power over Ethernet (PoE) switch and two interfaces for integrating with analogue two and four-wire intercom systems or other analogue sources.
Each station, including beltpacks, has an identical software engine programmed with 32 intercom channels. These can be programmed as a group of users, or as a single user for private conversations. Selecting a user on any station will extract that person's individual set-up configuration from the configuration software that is common to all other devices on the system.
Basic system parameters, including user configuration, can be set for each outstation, using the device's multi-function rotary-encoder control. Overall system configuration should be set using a laptop running Windows or MAC software downloaded from the Green-GO website. The laptop will facilitate naming user groups and individual operators and sending text messages via a device's LCD display buttons, to selected users.
Programme audio such as show-relay from the stage, or a sound track from a video, can be injected into or extracted from the system using dedicated analogue line-in or line-out ports on multi-channel stations or dedicated interface units.
The XLR4 headset connectors are compatible with headsets from Tecpro, Beyer and many other brands. If the microphone type is an electret, a switchable bias voltage is available. The useful Cue Light feature makes use of the multi-coloured LCD displays on outstations. 'Attention', 'Acknowledge' and 'Go' signals are presented as different colours.
An interesting feature of the Green-GO system is the use of General Purpose Input Output (GPIO) connections. These are available via 9-pin D-sub connectors on multi-channel stations and analogue interface devices, providing opening and closing contacts for external control interfacing.
Beltpacks
Green-GO beltpacks can store up to 32 of the available 250 intercom channels. Any two of the selected 32 can then be assigned to the two sets of channel controls on the beltpack. These two assigned channels can be easily replaced with alternatives if required.
Beltpacks incorporate three types of control - two 'Talk' buttons, a multi-function rotary encoder and an RGB back-lit LCD display button.
The LCD display button is used to send 'Call' or 'Alert' signals to either intercom channel and to display channel information including 'active channel' identification and short text messages sent from a laptop.
The two 'Talk' buttons activate their associated microphone circuit and offer push-to-talk (PTT) or latching modes. The rotary encoder is used for answering calls and is PTT only. It can also be used to adjust several parameters including the audio level of each circuit, changing channel assignments, adjusting microphone gain, setting noise-gate threshold and sidetone levels and loading beltpack user configurations.
'Call' signals are used to attract the attention of a colleague who has momentarily removed both beltpack and headset. To send a 'Call' signal, the intercom group that he/she is on is selected, and the LCD display button is pressed. This will cause the LCD displays of all other devices on that group to flash alternately red/blue. If the subtle approach fails, holding the LCD button down for three seconds will change the 'Call' into an 'Alert', triggering a loud buzzer. This feature should be used with care, to avoid startling other users on that group; the buzzer can be disabled if required.
Belt pack dimensions: 125 x 80 x 40 mm.
DECT Wireless System
The Green-GO DECT (Digital Enhanced Cordless Telecommunications) wireless system offers licence-free operation throughout the UK and Europe. Operation is full duplex, with clear audio quality, low latency and robust RF coverage. Call-alert and remote-mic-kill control signals are transmitted between Green-GO wired and wireless devices.
With a similar feature set to their wired counterparts, DECT beltpacks can access the same 32 channels, 250 groups, and 3000 users that wired user stations access.
DECT transmission power and frequency bands: 23 dBm, 1881MHz - 1897MHz, EU.
GO GGO-WBP DECT Wireless Beltpack
Green-GO DECT wireless beltpacks have a tough, lightweight ABS case with a spring-steel belt-clip on the rear. The bottom panel holds a removable battery with a locking screw, an on/off slider switch, a multi-colour LED indicator and a male 4-pin XLR headset connector.
The top panel supports a rotary encoder switch, a bright OLED multicolour display and four control buttons. The beltpack can be set for 2, 3 or 4-channel operation. In 4-channel mode, call alert signalling is not available. The Setup menu is accessed by holding down the rotary encoder and selecting the button located next to 'Setup' on the screen.
The rechargeable battery offers 5 - 6 hours of continuous talk and charge time is around 4 hours. For best performance, mains powered USB chargers are recommended (supplied). The battery is held in place by a single locking screw and may be swapped out if required.
Dimensions; 130mm x 95mm x 43mm. Weight: 400gm.
GO GGO-WAA DECT Wireless Antenna
GGO-WAA active wireless antennas use the same lightweight ABS case as the wireless beltpacks. They connect to the data network and are powered by PoE. If this is not available locally, a separate PoE capable network switch will be required.
With a single GGO-WAA antenna, typical RF coverage is between 50 - 300m depending on the local environment. Up to four wireless beltpacks may be registered to one antenna. A maximum of ten antennas can be employed providing sufficient DECT channels are available.
RF coverage can be increased by registering up to four antennas per beltpack. Antennas may be positioned behind obstacles like heavy walls that would normally be a major barrier to direct RF transmission.
Dimensions: 120mm x 95mm x 43mm. Weight: 220gm.
Multi-channel Desktop Stations
Multi-channel desktop stations have a compact footprint and are available in 8, 16, 24 and 32 channel versions. They provide a clear overview of many channels and offer a simple interface to listen and talk to selected channels. This makes the system suitable for complex live event and broadcast applications where several intercom channels need to be simultaneously monitored while conversing with one or more selected channels. Each channel identification is displayed on an LCD strip. The audio level of each circuit can be adjusted for best intelligibility.
Full duplex communication is by headset or the in-built loudspeaker and optional gooseneck microphone. Intercom channels are presented in banks of four and each channel is controlled by two rows of four switches. The upper row enables conversations with other stations on the selected intercom channel. These switches offer latching and non-latching modes, depending on the duration for which they are pressed. Each mic switch illuminates green, orange or red (blinking) to indicate talk to the channel, talkback from the channel, or 'Call' signal received. The lower row of switches operate in conjunction with the three 'Soft' keys and four 'Mode Select' keys in the Control Section to offer three functions; 'Listen' and 'Remote Mic Kill', 'Call' (to a group or individual) and 'Cue' modes. For improved listening, the 'Isolate' function will mute all intercom circuits that are not in 'Talk' mode, so unnecessary distractions are removed until the conversation is finished.
Multi-channel desktop stations may be powered from PoE (Power over Ethernet) or an external 12V DC power supply. The rear panel offers two Ethernet ports with built-in Ethernet switch. Port 2 can be used for power via PoE if no external 12V supply is available. This leaves Port 1 available for a laptop which may be connected for system set-up.
Line-in and line-out facilities are presented on 3-pin XLR connectors. They allow analogue audio to be injected into and extracted from the intercom system. A set of General Purpose Input Output (GPIO) connections are available on a D-sub 9-pin connector, providing opening and closing contacts to provide external control interfacing.
Rack-mounting Station
The 12-channel rackmount station has similar features to the desktop stations, but is designed to fit in a 2U of a 19 inch rack. The front panel can be angled outwards to make operation easier.
Wallmount Stations
Two wall-mounting outstations, based on the beltpack, are available. The external Ethernet connection is relocated inside the case and GPIO (2x in and 2x out) connections are available internally using screw terminals. The size of the LCD display is larger than that of the beltpack. Two versions are available; a speaker and microphone combination or a headset only alternative. A non-audio version is also available for information/cue-light duties.
Analogue Interfaces
Two audio interfaces are available for linking Green-GO intercom groups to external analogue intercom systems or other audio equipment. The 4-wire model will integrate Green-GO with analogue matrix or wireless intercom systems, while the 2-wire version is for linking to analogue party-line systems like Tecpro, Clear-Com and RTS-TW.
Each interface offers two Ethernet ports, programmable analogue input and output (two on the 4-wire interface) and a GPIO port. Powering is via PoE (from LAN port two) or from an external 12V DC supply. An LCD display and rotary encoder allow all settings to be viewed, selected and modified. This allows comprehensive control together with routing to and from the intercom.
Software
Green-GO configuration software is used to create and modify system set-up. It defines all groups, users channels and global settings and is available as a free Windows or Mac download from the Green-GO website.
Further details
It is impossible to cover every feature of a complex system like Green-GO digital intercom in a condensed product overview. For further details, the Systems Manual can be downloaded from the Green-GO website www.greengodigital.com.