運用記憶體映射法作PLC系統之遠端傳訊

Abstract

本文嘗試利用記憶體映射法，去建構一高彈性的遠端控制系統，以能適用各種的工作任務，並讓 PLC 的使用者能以最方便的方式來使用网路系統。記體映射法主要為在 PC 平臺的視窗環境開啟一可被多個行程取用的記憶體區間，定義為网路記憶體，並將此區間透過网路的處理機制維持多臺電腦的共用資料一致性。排序器的機制來提供可靠性高的記憶體映射能力，並具有相當的容錯力。本文亦設計了一些記憶體取用的方法以用於維持网記憶體的一致性，為了讓此网路系統能同時負擔多個任務，此系統被擴大為能夠處理多個群體的工作，本文將討論其管理的方法。而网路系統的傳輸速率也是很重要的，本文設計了一些方法，並分別說明其優缺點。 最後，本文以虛擬實境機器人安全防護系統和 Winplc系統兩個實例說明記憶體映射法的應用，和网路記憶體的規劃。

This thesis desicribes the method of memeory mapping to construct a highly flexible remote control system across the computer network capacity to accommodate working tasks. It also offer the most convenient way to utilize the networking mechanism for PLC users. The method of memory mapping need to create a common memory region defined the net memory which can be accessed by processes executing on the windows system of PC-based platform, and the net memory must maintain consistence among several computers on the network. A sequencer mechanism is constructed to provide a reliable network.system, and offer correspondent ability of fault tolerance. Some methods are designed to access the net memory for maintaining consistence of the net memory.This system has been extended to be able to handle groups in order to capacitate its ability of multitasking, and the group management is also discussed. The networking performance of this system is also important. Some techniques are develpoed to test it, and also their advantages and disadvantages are described respectively. At last, two realistic cases, the VR supervisory system for safeguard of the robotics, and the Winplc system, are implemented to illustrate applications of memory mapping, and the issue on planing of the net memory.