Based on the CAN bus of intelligent fire alarm system design (1)

This design of intelligent fire alarm system, using CAN bus III communications networks to fire for monitoring objects, using computer technology, testing and field bus technology, under the fire protection requirements and characteristics of the design, composition and work.

The system can both fires occurred early detection and automatic alarm and location under fire, timely output joint fire signal fire facilities, fire-fighting. Practice has proved that the system has a smart, responsive, high reliability, etc., can better meet intelligent building on fire prevention requirements.

1, introduction

Early prediction of fire has been put out the fire, reducing fire losses, protect life and property safety protection is indispensable to modern fire safety measures.

Fire auto-alarm and control system has been widely used in various types of construction and engineering. How to enable multiple independent systems constitute a unified fire monitoring network, is that we must look to solve urgent problems.

2. system composition

2.1 CAN bus

PROFIBUS CAN be used in the production of the bottom of a bus topology of the network, is currently the only international standard fieldbus, can realize fully distributed multiprocessor system, the number of nodes up to a maximum of 110, the transmission medium is twisted pair or fiber.

CAN bus with its strong anti-interference ability, the high communication speed and transmission distance, form the system simple and cost-effective high benefits in occupies the entire market, and intelligent region has been widely used, has been recognized as one of the most promising one fieldbus. Compared to traditional communication bus 485, CAN bus also has many advantages: work in a number of main mode, improved system reliability and spirituality; the perfect communication protocols can be used by the CAN controller chip and its interface chip, which greatly reduces the difficulty of developing the system, reducing the development cycle. At the same time CAN bus in larger data capacity of system network strong processing power and advantage, so CAN bus very suitable as a smart range of underlying network of trunk roads. It is precisely because of the advantages of CAN-bus, so this article uses the CAN bus formed by the three levels of traffic control systems.

2.2 L3 Communications control system

Based on the CAN bus of intelligent fire alarm system of chart shown in Figure 1.

The system consists of three levels of communication control system. This three-level communications control system are: first level: the master computer via RS-232 bus receive central controller alarm information; level 2: central controller via CAN bus receives regional controller alarm information; third-level: user-side automatic alarm in the alarm message via CAN bus transport to regional directors. This three-level network can consist of different network types, response, for a small area, the system can omit regional controller. Visible, the system for different objects to achieve an optimal price-performance and most extensive application coverage, improved product competitiveness and expansion of special convenience.

From where you can see in Figure 1, the system automatically by user-end alarm, regional directors, central controller and master computer four parts.

It works when the system is running, the user-side automatic alarm main complete onsite fire signal acquisition. When the user-side automatic alarm detects Aviso, via CAN bus transfer to the regional directors, through the regional controller transmitted to the community management monitoring center of central controller and to the relevant departments (Management Center or head of household) alarm signals. This system of the host computer also has a central controller received the alarm message via LED accurate display features, such as the floor, Aviso, area, door, and the fire mode, prompting security personnel to quickly confirm the Aviso, promptly rushed to the scene to ensure the safety of property and life in the laboratory. Due to the can bus from transmission line distance as well as the number of nodes, the node tolerances up to 110, therefore, for large and medium-sized area smart community, proposed a three-level control system of the programme, namely in central controller and client automatic alarms between joining regional controller. Following on the parts of the system described.

　

3. hardware design

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