(1) Telephone communication system
Realize the communication function of telephone (including three types of fax machines, video phones, etc.); star topology; use three types of (or above) unshielded twisted pair cables, and the frequency of transmission signals is within the audio frequency range.
(2) Computer Local Area Network System
It is the network foundation for realizing office automation and various data transmission; star topology; using Category 5 (or above) unshielded twisted pair cables to transmit digital signals, the transmission rate can reach more than 100 Mb/s.
(3) Music/Broadcasting System
Play music through speakers installed on site (such as shopping malls, stations, restaurants, guest rooms, corridors, etc.), and broadcast the scene through microphones; multi-channel bus structure; transmission of constant voltage output by power amplifiers (such as 120 V /120 Ω) audio signal to drive the sound of the live speaker, the transmission line uses copper core insulated wire.
(4) CATV signal distribution system
Distribute the cable TV signals evenly to each user point in the building; use branchers and distributors for signal distribution, in order to reduce signal distortion and attenuation, and make the signal quality of each user point meet the requirements of the specification, the wiring is a tree structure , and varies with the form of the building and the distribution of user points; 75 Ω RF coaxial cable is used to transmit multiple RF signals.
(5) Video surveillance system
Through the cameras, anti-theft detectors and other equipment installed on the site, the entrances and exits of the building and some important places are monitored and alarmed for abnormal situations; the transmission of video signals adopts a star structure and video coaxial cable; the transmission of control signals Adopt bus structure and use copper core insulated cable.
(6) Fire alarm system
The system consists of three parts: fire alarm and fire linkage system, fire broadcast system, and fire alarm intercom telephone system.
The fire alarm and fire linkage system monitors the on-site situation through the fire detectors and manual alarm devices installed in various places in the building. equipment to control the spread of fire, and its signal transmission adopts a multi-channel bus structure, but for the transmission of linkage control signals of important fire fighting equipment (such as fire pumps, sprinkler pumps, positive pressure fans, smoke exhaust fans, etc.), sometimes star-shaped Structure, signal transmission using copper core insulated cable (some products require the use of twisted pair).
The fire-fighting broadcasting system is used to instruct the on-site personnel to evacuate safely in the event of a fire. It adopts a multi-channel bus structure and uses copper-core insulated wires for signal transmission (the system can be used with music/broadcasting systems).
The fire alarm intercom telephone system is used to instruct the on-site firefighters to carry out fire extinguishing work.
(7) Entry and exit control system/all-in-one card system
Use computers, smart card door locks, card readers and other equipment to set, monitor, control and record the status of each entrance and exit to achieve unified management of all entrances and exits of the building to ensure building security. Its topology and transmission media vary by product .
(8) Parking lot fee management system
Through the induction coil installed under the entrance and exit ground, the entry and exit of vehicles are sensed, and the manual/semi-automatic/automatic toll management system is used to realize the toll collection and control the opening and closing of the electric railings. The wiring of the system is limited to the entrances and exits of the building yard. Each entrance and exit is controlled by a controller. The controller can work independently or be networked with the upper management computer. The wiring structure and transmission medium vary from product to product.
(9) Building automation system
Through various detection and execution devices connected with the on-site controller, various environmental parameters inside and outside the building and the working status of various equipment in the building (such as air conditioning, water supply and drainage, lighting, power supply and distribution, elevators, etc.) are detected. , monitor and control, and connect various on-site controllers through computer network to reasonably allocate and manage the resources and equipment in the building to achieve the purpose of comfort, convenience, saving and reliability. So far, there is no international standard for building automation system, and the communication protocols used by different manufacturers' products are different, and the topology and transmission medium of their field bus and control bus are also different. The following will briefly introduce the LonWorks technology and BACnet technology that are generally accepted and adopted by the international community.
In addition, there are video conference system, screen display system, sound reinforcement system, patrol system, building intercom system, automatic meter reading system of three meters (water, electricity, gas meter), etc. Buildings with different functions require different weak current systems.