• 전기의세계
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• 제18권6호
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• pp.33-45
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• 1969

The purpose of this paper is design the most important part of sequential control systems, that is, command-treatment part, from the signal-transformation point of view. An orderly procedure is developed by which for sequential control systems the experimental design method can be reduced to the rational design method. Important in this procedure are: 1. To make total block diagram of sequential control systems by determining input and output signals of command-treatment part. 2. To partition over-all block diagram by observing each output signal. 3. To design concretely minimum block diagram by using the operational block diagram. By applying the method for partitioning the circuit to the design, the design method for sequential control systems is organized and done rationally without the aid of experiece.

• Journal of Multimedia Information System
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• 제6권4호
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• pp.323-328
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• 2019

In this paper, a method of constructing an advanced sequential circuit over finite fields is proposed. The method proposed an algorithm for assigning all elements of finite fields to digital code from the properties of finite fields, discussed the operating characteristics of T-gate used to construct sequential digital system of finite fields, and based on this, formed sequential circuit without trajectory. For this purpose, the state transition diagram was allocated to the state dependency code and a whole table was drawn showing the relationship between the status function and the current state and the previous state. The following status functions were derived from the status function and the preceding table, and the T-gate and the device were used to construct the sequential circuit. It was confirmed that the proposed method was able to organize sequential digital systems effectively and systematically.

• 한국정밀공학회지
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• 제13권4호
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• pp.24-33
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• 1996

PLCs are vital components of modern automation systems, which have penetrated into almost every industry. Many industries have a demand for facilitation of PLC programming. In this study, a programning system for sequential control is developed on a personal computer. This programming system consists of two main parts, a GRAFCET editor and a GRAFCET compiler. The GRAFCET editor enables us to model an actual sequential process by a GRAFCET diagram. This GRAFCET editor is developed by the menu-driven method based on specific menus and graphic symbols. The GRAFCET compiler consists of two parts, a GRAFCET parser and a code generator. The possible errors in a drawn GRAFCET diagram are first checked by the GRAFCET parser which generates finally an intermediate code from a verified CRAFCET diagram. Then the intermediate code is converted into a control code of an actual sequential controller by the code generator. To show the usefulness of this programming system, this system is applied to a pneumatically controlled handling robot. For this robot, a Z-80 microprocessor is used as the actual sequential controller.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1986년도 하계학술대회논문집
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• pp.486-489
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• 1986

The transition diagram, as well as the regular expression, can be used as a formal description for a language acceptable by a finite automaton or for the behavior of a sequential switching circuit. But, if we are given one of these two descriptions, we shall find that it is not easy to get the other counterpart description. This paper is to show an easy method to find the equivalet regular expression from the transition diagram, by the aid of a graph-transformation technique.

• 조명전기설비학회논문지
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• 제19권3호
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• pp.127-133
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• 2005

PLC는 산업용 제어시스템에서 가장 많이 사용되며, 중요한 역할을 하고 있다. 이러한 PLC에서 사용되는 언어에 대한 연구도 활발히 이루어지고 있다. PLC에서는 LD언어가 가장 많이 사용되고 있다. LD언어는 데이터의 흐름을 알 수 없고, 유지보수가 어렵다. 반면에 SFC는 제어의 흐름을 이해하기 쉽고 유지보수가 용이하지만 조건과 인터록 기술에 문제점이 있다. 본 논문에서는 매니지먼트 스텝을 사용한 인터록의 기술에 대한 방법을 제안하였고, 실례를 통해 그의 타당성을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.134-136
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• 2007

Sequential Function Chart(SFC) is very easy to grasp the sequential flow of control logic and has the compatability for a maintenance, In process control, when an error is occurred, to execute other routine by force, we control the process by remote control. In this paper, we proposed the method of select sequence control by remote control in process control designed by Sequential Function Chart(SFC).

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.220-223
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• 2002

The digital logic systems(DLS) is classified into digital combinational logic systems(CDLS) and digital sequential logic systems(SDLS). This paper presents a method of constructing the digital sequential logic systems without feedback. Firstly we assign all elements in Finite Fields to P-valued digit codes using mathematical properties of Finine Fields. Also, we discuss the operarional properties of the building block T-gate that is used to realizing digital sequential logic systems over Finite Fields. Then we realize the digital sequential logic systems without feedback. This digital sequential logic systems without feedback is constructed ny following steps. Firstly, we assign the states in the state-transition diagram to state P-valued digit dodo, then we obtain the state function and predecessor table that is explaining the relationship between present state and previous states. Next, we obtained the next-state function and predecessor table. Finally, we realize the circuit using T-gate and decoder.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1985년도 하계학술회의논문집
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• pp.257-261
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• 1985

This paper deals with the personal computer based design for the sequential machines. Most part of sequential machine design have been implemented by using general purpose microprocessors in order to obtain the specific unctions required for their system. But, they have some difficulties in design stages. Knowledge of systems design method and high technology are basically applied to all the design stages.. Therefore ready made microcomputer system for personal use, personal computer, can be transformed to sequential machines by using the corresponding softwares and built-in personal computer input/output ports. Following the state transition diagram or table, we can obtain the ROM type of sequential machines directly and need not to design input/output interface except actuators and samplers because of capability of personal computer. Our main purpose of this design method are quick, flexible, reliable, modifiable circuit design of the sequential machines. In this paper, we use APPLE-II plus personal computer as target machine.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.233-238
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• 2000

CNC machine tool is assembled by central processor, PLC(Programmable Logic Controller), and actuator. The sequential control of machine generally controlled by a PLC. The main fault occured at PLC in 3 control parts. In LC faults, operational fault is charged over 70%. This paper describes diagnosis model and data processing for remote monitoring and diagnosis system in machine tools with open architecture controller. Two diagnostic models based on the ladder diagram. Logical Diagnosis Model(LDM), Sequential Diagnosis Model(SDM), are proposed. Data processing structure is proposed ST(Structured Text) based on IEC1131-3. The faults from CNC are received message form open architecture controller and faults from PLC are gathered by sequential data.. To do this, CNC and PLC's logical and sequential data is constructed database.

• 대한전자공학회논문지
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• 제24권5호
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• pp.823-832
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• 1987

This pper presents a method for constructing multiple-valued logic sequential machines based on Galois field. First, we assign all elements in GF(2**m) to bit codes using mathematical properties of GF(2**m). Then, we realized the sequencial machine circuits with and withoutm feed-back. 1) Sequential machines with feed-back are constructed by using only MUX from state-transition diagram expressing the information of sequential machines. 2) Sequential machines without feed-back are constructed by following steps. First, we assigned states in state-transition disgram to state bit codes, then obtained state function and predecessor table explaining the relationship between present states and previous states. Next, we obtained next-state function from state function and predecessor table. Finally we realized the circuit using MUX and decoder.