Below is a system example of a Clearcom system used at Ravensbourne. I will use this system as a guide to explain to nature of communication equipment in broadcast.
(http://www.clearcom.com/support/ravensbourne)
(http://www.clearcom.com/support/ravensbourne)
digital talkback matrix
The matrix can be regarded as the central junction of the 4-wire broadcast communication system. In this equipment, inputs and outputs, sources and destinations can all be assigned to allow communication between areas in the broadcast facility. The matrix routes the connections over the existing infrastructure of a broadcast facility with pre installed cable runs and equipment. Communication can be routed to:Talkback panels, cameras, four-wire boxes, radio talkback units, Integrated Service Digital Network (ISDN) lines and belt packs.
The matrix used at Ravensbourne is a Clearcom Eclipse-Pico shown in the image below.
The matrix used at Ravensbourne is a Clearcom Eclipse-Pico shown in the image below.
This unit can be controlled remotely via PC, either by a remote PC via the IP server or by directly connecting into the units RS232 port on the front of the panel. This allows the communications system engineer to directly configure the destination of each key on the systems many talkback panels.
The programmable mainframe of the system consists of a point-to-point matrix of switched cross points. These points are switches that electronically manipulating input and output lines to create various signal paths. This is represented in the image below.
The programmable mainframe of the system consists of a point-to-point matrix of switched cross points. These points are switches that electronically manipulating input and output lines to create various signal paths. This is represented in the image below.
Such is the importance of the digital matrix to the entire comms infrastructure that the physical unit has dual IEC power input sockets for redundancy needs that will allow automatic switchover should there be a power failure.
Audio connections to the unit are made via ports which are 9-pin RJ45/RJ11 connections. These CAT5 cables will carry audio to the radio talkback, ISDN and 4 wire circuits. For talkback panels they will also carry data signals over 2 wires. |
Avaliable in many formats and sizes to accomadate broadcast facilities individual needs. They can be mounted in desktop or from one to three 19-inch rackmount units. They include input for stalk microphones an internal loudspeaker or use with a headset.
http://catalogs.infocommiq.com/avcat/ctl1642/index.cfm?manufacturer=clear-com&product=v12ldx4y-ip
On this panel used at Ravensbourne (Clearcom V-series 12 Lever key panel) push buttons are used to talk to other programmable panels or external devices via the digital matrix. The user can control incoming volume levels via the adjustable volume control and also select which inputs to listen to via the loudspeaker.
The talkback panels can be configured remotely or via the Eclipse-Pico matrix as shown below.
The talkback panels can be configured remotely or via the Eclipse-Pico matrix as shown below.
This image is a screenshot of the Eclipse Configuration Software that is used to configure the entire system.
This image shows how the individual buttons can be configured to a individual users needs. In Ravensbourne the Concert Server is located in CAR. It enables people to communicate to any destination setup on the matrix via the Internet. It acts as a remote connection into the building to configure the system. |
wireless base-station & belt packs
A wireless base station allows communication to wireless belt packs. This unit is a Tempest 2400 basestation. This unit operates in 80MHz of spectrum in the 2.4GHz frequency range. This unit is connected over a 4-wire circuit into RJ45 ports via CAT5 connections. This unit allows roaming communications as long as care is taken to ensure low frequency interference. The RF wireless range can be expanded by integrating a wireless remote antenna station at a distance of up to 450m away from the basestation with CAT5/6 cable. Each user has a beltpack, this is the receiver unit that is combined with a headset to allow free-roaming operation. The appeal of beltpacks are there flexibility and ease of use. |
camera talkback
Camera talkback can operate with either 2 or 4 wire configurations with some including a separate 4 wire circuits for production and engineering talkback. Where there is only one 4-wire circuit present a 'talkback divert' system is used. E.g The camera usually receives production talkback but when the engineer keys to the camera his voice will also be heard. Any reverse talkback from the camera will be diverted to the engineer. When the key is released the talkback resumes talkback to production.
Each of the six camera CCUs have intercom functionality at Ravensbourne. From the matrix it connects to an audio DA which in turn connects to each Camera Control Unit . Comms audio sent or received to and from the Sony HXC-100 Cameras in the studio would be via the triax cabling. The CCU would transmit and receive various intercom/program/tally signal via the Intercom D-sub 25-pin on the CCU.
Each of the six camera CCUs have intercom functionality at Ravensbourne. From the matrix it connects to an audio DA which in turn connects to each Camera Control Unit . Comms audio sent or received to and from the Sony HXC-100 Cameras in the studio would be via the triax cabling. The CCU would transmit and receive various intercom/program/tally signal via the Intercom D-sub 25-pin on the CCU.
(http://www.ctpsystems.co.uk/camtb.html)
This unit is a camera talkback switcher from CTP Systems. This unit provides the talkback system for vision engineers up to 6 cameras. The unit provides a facility that allows the engineer to talk to all 6 cameras at once. XLR connections are provided for circuits to the cameras at the rear. |
telephone balance unit
Telephone Balancing Units (TBU's) such as the TEL-14 from Clearcom connect a 1/2 telephone line to a 4-wire system. This provides 2 full-duplex telephone links between the digital matrix and outside telephone lines over a CAT5 cable via a RJ-11 jack port.
The unit contains a automatic filtering process to improve clarity of the incoming telephone line. The unit is also optimised to sense incoming calls and automatically answer. The system works to minimise sidetone which is the sound of the operators own voice by using auto nulling. |
links
http://www.tvtechnology.com/default.aspx?tabid=204&entryid=6089
http://www.clearcom.com/support/ravensbourne
http://www.clearcom.com/upload/download/Clear-Com_Eclipse_V-Series_Panels_(810365Z).pdf
http://www.clearcom.com/product/digital-matrix/system-frames/eclipse-pico
http://www.clearcom.com/product/ip-communications/clear-com-concert/clear-com-concert
http://www.clearcom.com/product/digital-matrix/interface-modules/tel-14
http://www.clearcom.com/product/wireless/tempest2400/cm-222-tempest-2-channel-base-station
http://www.avs-us.com/download/Sony_HXCU-100_CCU_User_Manual.pdf
http://www.clearcom.com/support/ravensbourne
http://www.clearcom.com/upload/download/Clear-Com_Eclipse_V-Series_Panels_(810365Z).pdf
http://www.clearcom.com/product/digital-matrix/system-frames/eclipse-pico
http://www.clearcom.com/product/ip-communications/clear-com-concert/clear-com-concert
http://www.clearcom.com/product/digital-matrix/interface-modules/tel-14
http://www.clearcom.com/product/wireless/tempest2400/cm-222-tempest-2-channel-base-station
http://www.avs-us.com/download/Sony_HXCU-100_CCU_User_Manual.pdf