摘要:

The paper describes a range of software development facilities which have been implemented by the authors for a multi-microprocessor development system. This system is currently being used to investigate a variety of problem areas associated with implementing real-time embedded systems using multi-microprocessor techniques. A number of facilities are described including not only the software tools necessary for program development but also those for evaluating the performance of operational systems.

ISSN:1744-683X    

DOI:10.1049/sm.1984.0002

出版商:IEE    

年代:1984

数据来源: IET

摘要:

The paper presents an investigation into the design and operation of an intelligent controller for a multimicroprocessor-based fault-tolerant aircraft control system. This unit, called an asynchronous consistency unit (ACU), uses an interactive procedure and a mutual feedback mechanism (called synchronisation voting) for the timing control of the exchange of data among processors. Fault tolerance is achieved by majority voting of the exchanges between various processors. This is implemented by using both hardware and software techniques (hence the name hybrid). The ACUs govern the reliable operation of the system so that no module failure (processor, ACU or bus) has hard core characteristics; i.e. it cannot affect the reliable operation of the system, causing a catastrophic failure. The design provides full fault assertion for the ACUs and notification of failures to the processors. An ACU requires no master clock operation and it operates independently of its host processor in an asynchronous mode. A four-module system is presented. A disadvantage of this design is that the total number of data and control lines of the bus is substantial. If N data bits are exchanged in a four-module system, the total number of lines in the ACU is at least 4N+32. This disadvantage is, however, offset by the stringent requirement of full system fault tolerance in both the data and control signals of the aircraft control system.

ISSN:1744-683X    

DOI:10.1049/sm.1984.0003

出版商:IEE    

年代:1984

数据来源: IET

摘要:

The paper describes the principles of operation of a microprocessor-based instrument designed for use in the foundry industry. The instrument automatically determines the carbon and silicon content of molten cast irons by monitoring the cooling profile of a sample in a mould which contains a quantity of tellurium. The liquidus arrest temperature and solidus arrest temperature of the cooling profile of such a sample of unalloyed cast iron are related to the carbon and silicon content of the metal. Manipulation of the data produces an estimate of the carbon content of the molten metal to within 0.1% and, under certain circumstances, an estimate of the silicon content to within 0.14%. The automation of this process has resulted in high reliability of results, reduction in calculation time and elimination of subjective error present in manual analysis methods.

ISSN:1744-683X    

DOI:10.1049/sm.1984.0004

出版商:IEE    

年代:1984

数据来源: IET

ISSN:1744-683X    

DOI:10.1049/sm.1984.0009

出版商:IEE    

年代:1984

数据来源: IET