Earticle

원격기반 실시간 PLC 교육시스템은 인터넷을 이용한 e-laboratory 학습 시스템으로 실습실 환경에 시간적, 공간적으로 유연성을 제공하는 차세대 실습시스템으로 부각되고 있다. 본 시스템의 특정은 비교적 저가의 PLC를 이용하여 구축되었으며 저가의 일반 PC 카메라를 이용한 영상피드백 프로그램의 개발로 시스템 구축비용을 최소화 하였다. 실습 환경과 결과를 실시간 영상피드백으로 감시 할 수 있도록 하여, 인터넷 이용 실습이라는 흥미유발로 학습효과를 높일 수 있었으며, 실습에 직접 참여하지 않는 다수의 다른 학생들에게 동시에 실습 모니터링을 할수 있는 기회를 제공하였다.

Thanks to the spacial and timely flexibility of laboratory's environment, the distance learning based real time PLC education system has been brought into relief as a next generation laboratory alternative. The developed system was installed using a relatively cheap PLC and PC camera. Providing image feedback through the PC camera, the system provides the student's interests of the lab as well as an opportunity to monitor the lab's activities and results.

The recent control system has been changed into the type of PLC(Programmable Logic Controller) control. Up to now, systematic approach of PLC programming or control logic design is not suggested. In this study, the design process of the control logic is systematized and concrete process in each step is suggested. This systematized approach lead developer to be convenient to implement control system. When some error is occurred in the system, this approach enable the developer to analyze the reason of error rapidly and the system is amended according to systematic information of the analysis. The example of control system implementation following this approach is introduced.

In this paper, the implementation of a virtual Plant simulator for the PLC programming is presented. A virtual plant simulator that replaces function of transducers (e.g. pumps and valves) consists of a personal computer and a PLC(Programmable logic controller). Input/output conponents are edited on the monitor and are operated as the field transducers. The timing process for input/output components is analyzed. The data flow between a PLC system and a virtual plant simulator is carried out.

The programmable logic controller(PLC) programming has been manually carried out, which might cause the productivity decrease by omission and repetition of instruction. Recently, the knowledge-based automatic programming system is introduced. In the system, input/output(I/O) addresses are input by user. In this study, we developed the prototype system for automatic I/O addressing using knowledge-based technology, With the developed system, the PLC addressing task can he consistently and effectively performed.

In this paper, we present the application of knowledge-based system technique for generating of PLC ladder diagram The developed prototype system receives a time chart as an input and generates a ladder logic as its output This results in the computerization and intellegent processing of PLC programming. The system can be effectively applied to sequence control where the PLC programs need to be frequently changed and generated.

A structured user-friendly procedures which enable users to program in GRAFCET form directly from sequence specifications have been developed. Using these procedures, we can program the programmable logic controller (PLC) in sequential control and realize programming, debugging, and real-time monitoring. GRAFCET has many advantages like parallelism expression, so we can expect higher productivity and easier maintenance than boolean language or relay-ladder diagram specification when adapts them to PLC.

본 논문은 PID제어기가 포함된 PLC로 실제의 제어 시스템을 구성하는 일련의 과정을 제안하였다. PID 모듈 FM455C가 포함된 SIMATIC S7-400 PLC시스템을 일반 PC와 온라인으로 연결하여 PC의 윈도우즈 환경에서 PLC의 프로그램을 작성하였다. PID 제어기의 설계를 위하여, PID 모듈의 하드웨어 구성방식, 관련 소프트웨어 구성, 프로그램 작성 환경, 특히 P, PD, PI, PID제어기의 설계과정을 제시하였고, 이를 토대로 실물 제어대상, 도립진자 시스템에 대하여 PID제어기를 설계하고 모의/실물 실험을 통하여 성능을 확인하였다.

In this paper, a series of processes to configure a feedback control system by using a PID controller in a programmable logic controller (PLC). The PLC (SIMATIC S7-400) with a PID module (FM455C) is connected by online to an IBM PC with the Windows environment, which serves as a PLC programmer. PID controllers including P/PD/PI controllers have been designed in order to show design procedures, and finally, a PID controller for the plant of cart system. Performances of the control system have been investigated by the MATLAB simulation, the simulation in the PLC programmer. Physical performances have been recorded and examined for the real cart system.