• Title/Summary/Keyword: MAPN

Search Result 3, Processing Time 0.018 seconds

The MAPN Modeling for the distributed Data Allocation based on Multiple Aspects (다중 측면 기반의 분산 데이터 할당을 위한 MAPN 모델링)

  • Park, Seong-Jin
    • The Transactions of the Korea Information Processing Society
    • /
    • v.7 no.3
    • /
    • pp.745-755
    • /
    • 2000
  • In designing distributed databases, DAP(Data Allocation Problem) is one of the key design issues. Because, however, most of previous researches on DAP have considered only cost aspect, they cannot increase the performance and availability and they are not proper to the system requiring high-availability or real-time processing. Therefore, we need a more formal data allocation model considering multiple aspects. In this paper, we propose the MAPN (Multiple Aspects Petri Net) modeling method for the distributed transaction modeling. The MAPN model, an extended classical petri net, is proposed for the formal modeling considering multiple aspects (cost, performance and availability) concurrently. We demonstrate that we can compose the valid DAP evaluation model considering not only cost but also performance and availability concurrently by using the MAPN structure and MAPN graph.

  • PDF

Systematic Design of Programmable Logic Controller Based on Efficient Code Conversion Algorithm (효율적 코드변환 알고리즘에 기반한 PLC 의 체계적 설계)

  • Cha, Jong-Ho;Cho, Kwang-Hyun
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.7 no.12
    • /
    • pp.1009-1014
    • /
    • 2001
  • The ladder diagram (LD) for programmable logic controllers (PLCs) ar responsible for much important roles in advance industrial automation. As automated systems become more complex the design procedures of the system become more difficult as well. Hence. the design automation issues based on discrete event models(DEMs) are receiving more attention. One of the popular ways of tackling these problems is employing Petri nets. In this paper, we use the modified automation Petri net(MAPN) to model the manufacturing system and the modified token passing logic (MTPL) method conversion (ECC) algorithm based on the MAPN and the MTPL Finally, an example of the manufacturing system is provided to illustrate the proposed ECC algorithm.

  • PDF

Synthesis of Deadlock-Free Ladder Diagrams for PLCs Based on Deadlock Detection and.Recovery (DDR) Algorithm (DDR 알고리즘에 기반한 교착상태배제 래더 다이어그램 설계)

  • Cha, Jong-Ho;Cho, Kwang-Hyun
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.8 no.8
    • /
    • pp.706-712
    • /
    • 2002
  • In general, a deadlock in flexible manufacturing systems (FMSs) is caused by a resource limitation and the diversity of routings. However, the deadlock of industrial controllers such as programmable logic controllers (PLCs) can occur from different causes compared with those in general FMSs. The deadlock of PLCs is usually caused by an error signal between PLCs and manufacturing systems. In this paper, we propose a deadlock detection and recovery (DDR) algorithm to resolve the deadlock problem of PLCs at design stage. This paper employs the MAPN (modified automation Petri net), MTPL (modified token passing logic), and ECC (efficient code conversion) algorithm to model manufacturing systems and to convert a Petri net model into a desired LD (ladder diagram). Finally, an example of manufacturing systems is provided to illustrate the proposed DDR algorithm.