【文章內(nèi)容簡介】 re the system uses the distributional structure, The console is connected each part of control pitch point distributing in the building through the CAN Bus. System structure diagram like figure 1 shows The console hardware design The AT89C52 MCU is the primarily controller in console, It connects with the 共 4 頁 第 6 頁 warning module, the memory module, the clock/calendar electric circuit and the keyboard module. its structure drawing see Figure 2. The control pitch point also is controlled by the MCU, connected temperature examination module and the CAN Bus interface module. The system has used the AT89S52, it is a section low power chip that is produced by ATMEL Corporation, has 4 KB insystem programmable (ISP) FLASH memory integrated. The scene programming debugging and the system function changing is much conveniently flexible, using AT89S52 to take the system the master controller. When system normal work. The console send a definite control temperature value to a designate pitch point Distributed in the building through the CAN Bus. The pitch point receive the console?s orders and read the temperature detector DS18B20 temperature value distributed in each room through 1Wire bus, transmits each room temperature data and the number of room to the console through the CAN Bus. According to the definite temperature value which receives from console control the air gate of airconditioning system in each room. After receive the data a pitch point send to, the console reads the time from realtime clock/calendar chip PCF8563 through the I2C Bus, with the data which just received store to the memory AT24C128, then process each room temperature value. When the value achieve the data which is established from keyboard in advance, the console output warring to the alarm circuit on reports the alarm. Meanwhile the room number, the time and the temperature value delivers the LED display circuit to display. Every room alarm temperature value is established through the keyboard input module, the console process value and stores in the memory corresponding the input. The CAN Bus interface design The CAN Bus corresponds high as 1 Mb/ s, the most longdistance range may reach 10 km。 The CAN Bus corresponds using the short frame structure, spends the data transmission time shortly, so the probability which disturbed is low, and the CAN Bus has good error detecting measures, therefore its reliability is high. In the CAN Bus work each pitch point has an address, any pitch point theoretically can be increased, deleted in the work based on CAN Bus. In the practical application, the CAN Bus work most access 110 pitch points. The work munication method may for the pointtopoint way or for the broadcast way, May be the single host way or many hosts way. Therefore, the CAN Bus correspondence has the suitable flexibility. The transmission correspondence information frame can establish the different priority based on the CAN Bus and higher priority information frame can be transmitted first and promptly through the Bus information arbitration mechanism. This increase more important information can promptly transmit, increase the CAN Bus correspondence timeliness. The CAN Bus work suits the mercial processing monitor equipments by its remarkable characteristic, the inexpensive price, the extremely high reliability and the nimble structure. The pitch point core ponent is CAN controller SJA1000 which is PHILIPS Corporation produced and CAN driver PCA82C250[3]. SJA1000 is the integrated independent CAN controller (is pletely patible with PHILIPS early CAN controller PCA82C200). It responsibly pletes the CAN Bus correspondence protocol function of the physical layer and the data link layer. SJA1000 internal has the control register, orders the register, th