【 Weak current College 】 video multiplexing in fire alarm monitoring system---Power By 【 China power house network 】

The city fire remote monitoring system technical specifications on the standards since 1 January 2008. The advanced technical means and fire technology integration, improving the urban fire fighting ability. Establishing urban fire remote monitoring network, fire safety key unit of automatic fire alarm system anomalies are found, you can even transfer over the network notification real images to fire monitoring center, on the automatic fire alarm information available through video, audio and data accessibility, to ensure that the fire alarm authenticity and reliability. The fire destroyed in the bud, thereby avoiding substantial property damage and casualties.

Nearly 2 years, many cities are for the remote monitoring system of urban fire alterations and extensions, including Fujian Ningde city fire video monitoring system has been started, 355 fire surveillance camera will appear in the city's major intersections. Fuding building fire video surveillance system, set in Fuding city 60 camera collecting data while combining Fuding city fire characteristics, in particular in the old town of huts the contiguous zone set up four fire special camera. The system adopts advanced all networked, digital signal transmission system to achieve, over dispersion, independent image collection point for networking, across regions, the whole network-wide unified control, unified storage, unified management, resource sharing, geographical restrictions have been eliminated, the entire system can realize real-time remote surveillance, history stored queries, and remote control management and other functions. Data acquisition through remote camera via the Internet after transfer to the Terminal Server for data processing, final image clearly sent to city police 110 command center with large screen TV. To focus on community, street, fire key regional and site implementation networking monitoring, to the correct conclusion based monitoring area fire safety conditions to provide accurate information to ensure that in the event of fire, the fire brigade can quickly and accurately, timely disposal, will fire caused by people's lives and property losses reduced to a minimum.

In video surveillance applications for many years in the field of coaxial cable video multiplexing transmission technology has made new breakthroughs in a coaxial cable can transmit multiple video and audio images, it also can monitor indoor 70 ~ 120V pressure broadcast signal transmission to the monitoring point, video and two-way audio broadcasting intercom functionality. This new technology not only enables audio and video synchronization-transfer talk features, with a substantial saving of wire and construction costs, is ideal in fire video system applications.

Video multiplexing technology principle

We can see from the cable TV clear video images and high-quality sound, you can choose from hundreds of channel programs. Coaxial video multiplexing is in cable TV technical development. Its basic principle is 0 ~ 8MHz video baseband signal modulated to 49.75 ~ 860MHz high frequency band, the way each 8MHz bandwidth modulation signal, after modulator modulation of high-frequency signal through the branch mixer coupled, thus achieving a cable on multi-channel audio and video signals, while the reverse transfer broadcast respectively, RS485 control signal, power supply, etc. This cable TV technology reverse application in the monitoring system is often called the common first-line pass transfer, video monitoring application field has for many years.

Video multiplexing technology including: single cable line pass, one-way dual video multiplexer, video-third part products.

Video Multiplexing technique new development

Use of cable TV technology transfer audio and video technology has been very mature, but monitoring system often have a PTZ control camera, this requires the transmission of audio and video signal and RS485 control signal transmission. Traditional technologies are in the Terminal to control signal modulation by active modulator to 38MHz and coupled to the mainline transmission to front-end on the reverse, in front through active demodulation out RS485 control signal. This way you can transfer audio and alarm signal, but this kind of transmission error rate is high, poor stability, high costs.

New transport technology does not require the RS485 control signal modulation, using passive transparent transmission technology, the transmission of signals does not require a modem, stable and reliable performance. This transport technology not only can transmit RS485, code, control signals, you can transfer 70 ~ 120V high level of radio signal at constant pressure, phone signal, etc.

Video multiplexing video intercom bi-directional audio broadcasting

1, single video two-way audio broadcasting multiplexer

Single channel video, bi-directional audio broadcasting multiplexer is a root SYWV75 or SYV75 cable transmission 1-channel video signal, 1-channel audio signal and 1 channel reverse pressure broadcast signals. Surveillance camera output video signal and the output of audio signals for pick-up as input to the transmitter, and a modem to 38MHz frequency transmission by cable, the Terminal sink demodulation video and audio signals, video signals but allocator is to monitor, matrix, hard disk recorders, audio signal through the amplifier output to speakers.

2, dual video bi-directional audio broadcasting intercom multiplexer

Dual video two-way audio broadcasting multiplexer is a root SYWV75 or SYV75 cable on 2-channel video signal, 2-channel audio signal and 1 channel reverse pressure broadcast signals.

3. multichannel video intercom bi-directional audio broadcast signal a wire-transfer system

Use of video surveillance system signal line-transmission technology, the transmission on a single coaxial cable 16-channel audio and video signal and reverse the constant pressure of broadcasting signals. In front of each camera is equipped with an audio/video broadcast modulator, the camera's video signal and the audio signal modulation pickups to different frequency, output pressure loudspeakers broadcast signals received. Terminal modem will meet different audio and video, while adjusting them to constant pressure reverse transmission broadcast signal to front modulator.
Video multiplexing technology applied to the periphery and fire alarm monitoring systems

Now video surveillance are increasingly applied to fire protection systems, video surveillance can confirm the secondary fire protection systemThe accuracy of the fire alarm, record all processes of fires, the development of Visual observation of fire, assisted decision-makers in a timely manner to make accurate judgments, take the right measures to enable personal security and economic losses due to minimal.

The fire system, emergency broadcast many prerequisites, some systems but also with fire emergency telephone. Video bi-directional audio broadcasting reuse technology applications, not only can you implement fire emergency broadcast functionality and fire alarm phone features, you can monitor the video screen at the same time achieve and fire Monitoring Center for Talkback. With a SYWV75 or SYV75-5 cable, you can realize long-distance multiple signals transmitted simultaneously. Video multiplexing technology of high-frequency modulation characteristics, making it a antijamming, anti-static characteristics.

1, single and dual video two-way audio broadcasting multiplexer applications

In fire-fighting system, video surveillance and bi-directional audio broadcasting intercom points very decentralized, single-cable required cloth for single or dual video two-way audio and video broadcasting transmission. Cable can use SYWV-75 RF cable, connect as in figure (brief).

2. multi-channel video intercom bi-directional audio broadcast signal a wire-transfer system

Common first-line pass transport system can be transmitted on a cable 8-channel audio/video and radio signals. When the transmission distance of more than 100 m, monitoring points are more dispersed, and partition fire protection requirements of broadcasting, you can use a single cable line through transmission mode.

Signal line is the tree structure, you can enable distributed monitoring points nearest to the main transport route. It is each extension on the transmission of a signal through a branch to the trunk line mixer coupling on the transfer, at the receiving end by 8 multifunctional inserter received a special modem. Broadcast signals through a multifunctional inserter reverse transfer to front-end modulator connection radio speakers.