【正文】 this satisfied all our memory and 1/0 requirements at the local station side.4 System implementationThe local station: Fig. 3 is the block diagram of the circuit used to utilize the MC68HCllA4 as a remote fire detecting circuit while Fig. 4 illustrates the same circuit in an expanded form. It can be seen that the single microcontroller can be used to monitor more than one detector, thus reducing system cost. Closed loop connectionsThe loop power supply, which is usually between 28 and 26 V, is further regulated by a 5 V 100 mA monolithic low power voltage regulator to supply power to the microcontroller. The onboard oscillator, coupled with an external crystal of MHz, supplies the microcontroller with its timing signal which is divided internally by four to yield a processor frequency of kHz, which is an even multiple of the RS 232 [7] baud rate generator. In this Section the term ‘supervised input or output’ will be used to mean that the function in question is monitored for open and shortcircuit conditions in addition to its other normal functions. More information can be found in Reference 9.5 Main loop Main loop flow chart6 ConclusionThis paper describes the development of a large scale fire detection and alarm system using multisingle chip 。 this facilitates serial munication.(e) It has an a/d converter on board。 the central or the top level provides the lower units with a model of the relationship between its action and the response of the system.It is evident that a powerful machine is required at this stage so that all the required functions can be implemented. The availability of the new generation of microchips makes this architecture a feasible solution.A single chip microputer was chosen over discrete digital and analogue devices to interface to the field devices and to the central microputer. This is the main reason that previously this approach was not feasible.In selecting the microputer for the local stations, the criterion was the requirement for a chip which contains the most integration of the analogue and digital ports required for the interface and the utilization of CMOS technology owing to remoteness of the local stations. The choice was the Motorola 68HC11A4, for the following reasons:(a) It is CMOS technology。致謝致謝人： 參考文獻[1][J].電子制作,2007,154(1):1212.[2][J].電子制作,2006,149(8):6263. [3][J].家庭電子,2004,156（2）:1920[4]趙婷. 美國煙霧報警器的統(tǒng)計報告[J].消防科學(xué)與技術(shù),2010, 151(3):183184[5][M].北京:北京航空航天大學(xué)出版社,2004.[6]李永生,[J].儀表技術(shù)傳感器,2002,148(3): 19.[7][J].儀器儀表用戶,2006,13(5): 12.[8][J].電腦開發(fā)與應(yīng)用,2007,20(11):6062. [9][M].西安:西安電子科技大學(xué)出版社，2009.[10][M].北京:高等教育出版社,[11]華成英,[M].北京:高等教育出版社,[12] Wang Xi huai，Xiao Jianmei，Bao Minzhong. Multisensor Fire Detection Algorithm for Ship Fire Alarm System Using Neural Fuzzy Network[J]. Signal Processing Proceedings. 2000，16(11):16021605.[13] James A. Milke. Monitoring Multiple Aspects of Fire Signatures for Discriminating Fire Detection[J] .Fire Technology, 1999,35 (3)：2526 .[14] Tomkewitsch R. Fire detection systems with distributed Intelligence the puls polling system[J] .Fire Safety Journal, 1993,96 (6) :225231 .附錄A 英文文獻原文Multiple singlechip microputer approach to fire detection and monitoring system . AIKhalili, MSc, PhDD. AIKhalili, MSc, PhD. Khassem, MScIndexing term : Hazards, Design, Plant condition monitoringAbstract: A plete system for fire detection and alarm monitoring has been proposed for plex plants. The system uses multiple single chip architecture attached to a party line. The control algorithm is based on a twolevel hierarchy of decision making, thus the plexity is distributed. A plete circuit diagram is given for the local and the central station with requirements for the software structure. The design is kept in general form such that it can be adapted to a multitude of plant configurations. It is particularly shown how new developments in technology, especially CMOS single chip devices, are incorporated in the system design to reduce the plexity of the overall hardware, . by deposing the system such that lower levels of hierarchy are able to have some autonomy in decision making, and thus a more plex decision is solved in a simple distributed method.1 IntroductionRegulatory requirements for most high risk plants and buildings mandate the installation of fire detection and warning systems for all sensitive areas of the plant or the building. Most fire codes state the requirement for monitoring and control specifically related to a type of a plant or building such as chemical plants, petroleum, nuclear plants, residential highrises etc. A general conclusion of these codes can be specified as the following requirements :(a) The source of all detector signals should be exactly identifiable by the central station(b) An extra path of munication between the central station and all local controllers(c) Direct means of control of alarm and central equipment by the central station(d) Means of munication between the central station and the fire department(e) Availability of emergency power supply. The codes usually also specify the types and frequency of tests for all equipment.A fire detection and alarm system is a bination of devices designed to signal an alarm in case of a fire. The system may also acplish fan control, fire door hold or release, elevator recall, emergency lighting control and other emergency functions. These additional functions supplement the basic system which consists of detection and alarm devices and central control unit. Technology has an influence on system architecture. When technology changes, the architecture has to be revised to take advantage of these changes. In recent years, VLSI technology has been advancing at an exponential rate. First NMOS and, in the last year or two, CMOS chips have been produced with the same packing density with more gates per chip yet at a low