The development course of domestic building intercom system

The development course of domestic building intercom system
The development of building intercom technology has gone through four stages:
Building intercom, also called the building door bell, in the construction of our country's small

intelligent although late, but the development of high and new technology change rapidly. Along

with the Internet
Net popularization, many communities have realized broadband access, information superhighway has

laid into the cell and enter the family. Intelligent community system based on TCP/IP
Technology conditions have been met. Basic operation of the intelligent system is changing from

small on-site bus to Internet, from decentralized management to centralized management
Physical changes.
The historical experience of building intercom system:
First generation
The earliest building intercom products have single function, only the unit talkback function,

since the late 80's of 20th century, China has begun a (4 N) single user visible
The intercom and unit type intercom products available. The system only uses code, decoding

circuit or RS-485 for small areas within a single building communication, not
The whole area of large area network. This system of decentralized control, incompatible, act of

one's own free will, unified management is not conducive to residential, system function
The relatively simple. At that time, the capacity of the market is smaller, intercom products

have individual manufacturers in Guangdong area, the user in guangdong. Visual intercom product
Main Korea, Taiwan brand, one by one, mainly sold in Shanghai, guangdong. Annual demand in

domestic market less than one hundred thousand households.
1993-1997 is the first stage of the development of the domestic market, Guangdong area appeared

several professional manufacturers, these manufacturers products began to scale production
Production, technology continues to progress, unit building type intercom and visual intercom

users continue to show growth momentum, concentrated in the real estate market to start earlier

Guangdong
Shanghai, and other economically developed city.
The second generation
With domestic demand increased gradually, the original no networking and invisible requirements

have been unable to meet, then enter the network stage. Nineties
Initial products occupy more brand in Taiwan. In the late 90's, especially after 1998, the

network has become the basic requirement of intelligent building. Therefore
Small, control network technology, fieldbus technology is widely using single-chip computer

technology. Such as CAN, BACNET, LONWORKS and domestic AJB-BUS,
WE-BUS and using RS-485 technology to realize the bus etc.. Using these techniques can make

system interconnection network, unified area of disperse
Management, coordination, so as to form a relatively large area system. Application of Fieldbus

Technology in the community, the intercom system forward
A big step.
Building intercom products to enter the second period of rapid development, large community

network and integrated intelligent building intercom equipment began to emerge. After the 2000
The development of the demand for capital city building intercom products rapidly, some

manufacturers are also increasing rapidly, formed the two major manufacturers in the Pearl River

Delta and Yangtze River Delta region
Industrial cluster; the Pearl River Delta in Guangdong, Fujian; Yangtze River Delta in Shanghai,

Jiangsu.
Demand from the market perspective, the product has entered the demand platform area. After a

large number of applications, the traditional bus visual intercom system also showed some
Limitations.
The 1 poor anti-interference ability. Often sound or image interference is not clear phenomenon
2 limited transmission distance. Long distance when the need to increase the video amplifier,

large area network difficult, and cost is higher
3 using the bus system, especially busy, because the same audio video bus allows only two calls,

cannot achieve household call
4 single function, most of the products are limited to call, the lock function, equipment

utilization rate is very low, due to technical limitations, the upgrading of products or
Expand the functions of difficulties.
The lack of standards and 5 industry, the difficulty of integration system, between different

manufacturers products are not interconnected, and visual intercom system is very difficult and

other weak electronic
System interconnection, can not be shared community integrated wiring, installation amount is

large, the service cost is high, also not very well into the community of integrated network.
So in 2000, the network launched a visual intercom system, control the digital signal using the

network cable, audio and video using coaxial cable transmission of buildings
Intercom system, therefore the need for the two sets of line wiring. This system breaks the

traditional bus architecture, building intercom systems for the transition to digital stage,

provides
Feasibility of witness. It belongs to the 2.5 generation products.
The third generation
Visual intercom function (LAN)
From 2001 to 2003, with the rapid development of computer technology and the popularization and

application of Internet, so that the people's work, life has undergone tremendous change
, the concept of the digital, intelligent community has been accepted by more and more people,

building intercom products to enter the third period of rapid development, multi function
Said equipment have begun to emerge, LAN technology development product ARM or DSP technology

based on digital communication technology gradually introduced, the development of a

breakthrough! Net
The network transmission of data, fuzzy concept of distance, can be extended indefinitely. Break

through the traditional idea, can provide value-added network services (e.g., can also provide

video phone,
Advertising and other functions, and low cost). The security system integration into the

equipment, improve equipment availability. The main advantages of:
1 suitable for complex, large-scale and ultra large scale community network demand
The indoor machine 2 digital implementation of the digital voice, image, through a cable

transmission, which need not be distributed data bus, audio and video lines.
As long as the digital room