• Nuclear Engineering and Technology
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• v.45 no.4
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• pp.477-488
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• 2013

The PLC (Programmable Logic Controller) has been widely used to implement real-time controllers in nuclear RPSs (Reactor Protection Systems). Increasing complexity and maintenance cost, however, are now demanding more powerful and cost-effective implementation such as FPGA (Field-Programmable Gate Array). Abandoning all experience and knowledge accumulated over the decades and starting an all-new development approach is too risky for such safety-critical systems. This paper proposes an RPS software development process with a platform change from PLC to FPGA, while retaining all outputs from the established development. This paper transforms FBD designs of the PLC-based software development into a behaviorally-equivalent Verilog program, which is a starting point of a typical FPGA-based hardware development. We expect that the proposed software development process can bridge the gap between two software developing approaches with different platforms, such as PLC and FPGA. This paper also demonstrates its effectiveness using an example of a prototype version of a real-world RPS in Korea.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.131-133
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• 2005

In this paper, we proposed the program module that expand output points when increased of the output machine for the design of process control system with PLC. In order to incense output points we need the decoding. There is a hardware decoding and a software decoding. In this paper, we proposed the decoding program module which is a software decoding and confirmed feasibility through a simulation.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.4
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• pp.297-303
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• 2005

In this paper, I developed an intelligent multi agents based softPLC(IMPLC). In IMPLC, the standard IEC 1131-3 PLC languages(LD, SFC, FBD, ST) programmed by a user are converted to IL, which is one of intermediate codes, in order to make them interactions. And then the IL is converted to the standard C code regarding some extension and transplanting, which can be used in a commercial editor such as visual C++. In IMPLC, the logical errors and syntax errors occurred by users are detected, so that the optimal PC control based softPLC can be possible. IMPLC provide easy programming platform to such beginner as well as professionals. The study of code conversion is firstly tried in the world as well as KOREA. I applied IMPLC to 3 steps conveyer belt system. The simulation results say that the debugging steps by IMPLC using multi agents are decreased than the conventional softPLC's.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.40 no.5
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• pp.306-316
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• 2003

본 논문에서는 소프트웨어 PLC를 구현하는 방안을 제시하였다. 하드웨어는 표준적인 산업용 PC와 입출력 보드들로 구성된다. 운영체제로는 수십 마이크로초의 정밀한 단위로 태스크들의 스케줄링이 가능한 실시간 리눅스를 사용하였다. 소프트웨어 PLC를 위해 개발한 실시간 태스크들은 실시간 리눅스의 커널 모드에서 실행되며, 사용 목적에 따라 작성된 PLC 프로그램을 해석하고 실행하는 작업을 일정한 주기로 반복한다. 또한 PLC 프로그램을 편리하게 작성할 수 있도록 자체 프로그램 문법을 제안하고 이를 위한 컴파일러도 구현하였다. 이렇게 구현된 PLC는 가격 대비 성능이 우수하며 소규모의 응용분야들에 유용하게 활용할 수 있다.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.2
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• pp.207-215
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• 2004

The PLC programming by IEC1131-3 is hard to handle to ordinary users as well as professionals. Also it has not a generality, so that it couldn't be debugging some logic errors easily. In order to be adapted for such environment, In this paper, I have developed the ISPLC(Intelligent Agent System based Software Programmable Logic Controller). In ISPLC system, LD programmed by a user is converted to the C code which can be used in a commercial editor such as Visual C++. The detection of logical errors in C code is more effective than PLC programming itself. ISPLC provides the GUI-based interface in web environment and an easy programming platform to such beginners as well as professionals. The study of code conversion of LD to IL as well as IL to C is firstly tried in the world as well as KOREA. To show the effectiveness of the developed system, I applied it to a practical case, a real time traffic control system. ISPLC is minimized the error debugging and programming time owing to be supported by windows application programs.

• Journal of KIISE:Software and Applications
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• v.32 no.12
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• pp.1271-1282
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• 2005

Recently, PC-based control is incredibly developed in the industrial control field, but it is difficult for PLC programming in PC. Therefore, I need to develop the softeware PLC, which support the international PLC programming standard(IECl131-3) and can be applied to diverse control system by using C language. In this paper, I have developed the ISPLC(Intelligent Agent System based Software Programmable Logic Controller). In ISPLC system, LD programmed by a user which is used over $90\%$ among the 5 PLC languages, is converted to IL, which is one of intermediate codes, and IL is converted to the standard C rode which can be used in a commercial editor such as Visual C++. In ISPLC, the detection of logical error in high level programming(C) is more eaier than PLC programming itself The study of code conversion of LD->IL->C is firstly tried in the world as well as KOREA. I developed an execution engine with a good practical application. To show the effectiveness of the developed system, 1 applied it to a practical case, a real time traffic control(RT-TC) system. ISPLC is minimized the error debugging and programming time owing to be supported by windows application program.

• Proceedings of the IEEK Conference
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• 2001.06c
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• pp.105-108
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• 2001

In this paper, "The PLC Controlling on Web Browser" is designed and implemented to remote control and to monitor FA system. Protocol bidirectional communication with PLC is written and sotted. Then Administration system sets Web server and JAVA Sevelet Program. The client system located at the monitoring Web browser are a JAVA Sevelet base system, and sends some commands to the server system which guards and controls the PLC system. The commands are delivered to the server system and the driver software exists in the server controls the PLC system directly.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.11b
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• pp.557-560
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• 2003

In this paper, we developed an editor and running engine for the SoftPLC. LD is the most popular standard IEC 1131-3 PLC language in Korea and used over 90% among the 5 PLC languages. In this paper, we have developed the ISPLC(Intelligent Agent System based Software Programmable Logic Controller). In ISPLC system, LD programmed by a user is converted to IL, which is one of intermediate codes, and IL is converted to the standard C code which can be used in a commercial editor such as visual C++. In ISPLC, the detection of logical error in high level programming(C) is more efficient than PLC programming itself. ISPLC provide easy programming platform to such beginner as well as professionals. The study of code conversion of LD-> U->C is firstly tried in the world as well as KOREA.

• Korean Journal of Computational Design and Engineering
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• v.14 no.3
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• pp.176-185
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• 2009

Modern manufacturing systems consist of highly automated manufacturing devices, and they are controlled by complicated PLC programs. To make sure the achievement of the control objectives of a manufacturing system, it is very important to monitor the dynamic system behaviors of the manufacturing system. In this paper, we propose a monitoring methodology of a PLC program based on the Software In the Loop Simulation(SILS), which makes use of the time gap information between PLC signals. The errors relevant with PLC signals can be found using the proposed methodology, comparing a normal PLC signal trajectory with a target PLC signal trajectory. The proposed methodology has been implemented and tested with simple examples.

• Journal of Computing Science and Engineering
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• v.11 no.1
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• pp.9-23
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• 2017

NuDE 2.0 (Nuclear Development Environment 2.0) is a formal-method-based software development, verification and safety analysis environment for safety-critical digital I&Cs implemented with programmable logic controller (PLC) and field-programmable gate array (FPGA). It simultaneously develops PLC/FPGA software implementations from one requirement/design specification and also helps most of the development, verification, and safety analysis to be performed mechanically and in sequence. The NuDE 2.0 now consists of 25 CASE tools and also includes an in-depth solution for indirect commercial off-the-shelf (COTS) software dedication of new FPGA-based digital I&Cs. We expect that the NuDE 2.0 will be widely used as a means of diversifying software design/implementation and model-based software development methodology.