Use the intercom system several kinds of transmission mode

Because the LONWORKS signal to control the special control chip prices high, the network itself can only transmit data signal, the audio and video signals cannot pass on it
Lose, limit its use in the intelligent system, especially the limit its use in building intercom and in monitoring system.
Signal transmission mode 1, ordinary building intercom usually use
In the building intercom system at present, due to the cost of production and technology, the widespread use of audio and video is the baseband transmission mode, the data signal
Transmission, commonly used RS485 way therefore, building intercom systems in general, usually with at least four core wire (a audio line, two signal lines, a piece of land
Transmission line) with a video line. The signal transmission line, complex wiring, signal transmission distance, high cost, wiring, debugging difficulties
Hard. Tandem network, increase the transmission distance of the line, increased the probability of the emergence of these problems. Once the network failure, only half
Days, many manufacturers in the coordination and guidance to several days, can repair system. Residential property management personnel, maintenance of intelligent system
Relying too much on manufacturers, once the manufacturers service does not follow to go up, it will bring many negative effects to the small property management, according to "China market report", now
The intelligent community of three to five year system about 35% paralysis, and system 30% is not normal, the system only 20% more to normal use
.
Connection mode is usually used for building intercom system 2, multi line system
One is the use of screw pressing the backlog of signal lines, the benefits are: terminal pressure connection is reliable. But the wiring, easy to take the wrong line, special
Don't be system installation, commissioning, maintenance of a lot of trouble.
Another method is to use the connection mode of joint air. It is the use of connection mode of joint air, while the installation, demolition
Preparation of speed, facilitates debugging and maintenance, repair, but the temperature and humidity higher area, should not be used, because when the temperature and humidity
When the metal joint, butt, easy oxidation, mildew, caused by poor contact, make the system higher fault rate, that many engineering examples, in some
High temperature, high humidity areas, then quickly half a year, the slowest one to two years, more than doubles the occurred fault.
3, system adopts the connection mode
Signal transmission network and equipment system is adopted for the two-way cable TV network design of the coupling device, the joint is stable and reliable, good sealing performance,
Have good shielding the signal line, not easy to mold, and the connector, pull convenient. Waterproof joint outdoor for long time, threw into the water will not make line
Road of any fault.
Source: China building talkback network