• Title, Summary, Keyword: PLC

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Bacillus cereus에 의한 Phospholipase C (PLC) 생산

  • Seo, Guk-Hwa;Lee, Jong-Il;Bornscheuer, Uwe T.
    • 한국생물공학회:학술대회논문집
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    • pp.232-234
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    • 2002
  • Bacillus cereus secretes a nonspecific phospholipase C (PLC) that catalyzes the hydrolysis of phospholipids to yield diacylglycerol and a phosphate monoester. This study focuses on the production of PLC by B. cereus and recombinant E. coli with fusion protein gene (plc::gfp). Fermentation processes have been monitored by a 2-dimensional fluorescence sensor.

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A Study on Development of Home Network on PLC (PLC기반 홈네트워크 구축에 관한 연구)

  • Kang, Young-Goo;Jin, Jin-Yu;Yang, Hae-Sool
    • Proceedings of the Korea Information Processing Society Conference
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    • pp.25-27
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    • 2008
  • 전력선을 이용한 PLC기술은 경제성과 접근의 용이함으로 현재 많은 각광을 받고 있는 첨단기술이다. 최근 국내외 PLC 핵심기술을 활용한 부가서비스가 개발되고 시장규모가 커짐에 따라 PLC 네트워크 기술의 중요성이 커지고 있다. 본 연구에서는 PLC 핵심기술을 이용해 방범, 가스제어, 조명제어, 가전기기 제어, 도어락 제어, 영상감시, 휴대폰 영상통보 등 기능을 갖춘 PLC 기반 통합관리 네트워크를 제안하고자 한다.

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On-line PLC Laboratories Using Distance Learning (원거리 학습을 이용한 실시간 PLC 실습)

  • Lee, Sung-Youl
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • pp.310-315
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    • 2005
  • This paper describes the development of on-line Programmable Logic Controller (PLC) laboratories to teach the detailed operation of a PLC using distance learning approach. The PLC has become a key component to provide intelligence for machines in CIM environment. This study introduces a case study that teaches PLC programming in distance learning environment. The study describes the contents of PLC laboratories and workstation set ups. The study concludes with problems found and proposes the ways to improve the on-line laboratories.

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A Study on a Communication Data Item and Method in PLC communication with Computer for FA Information System (FA정보시스템에서의 PLC 정보처리에 대한 연구)

  • Lee, Hun-Joon;Kim, Young-Tae;Kim, Sung-Kwun
    • IE interfaces
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    • v.8 no.3
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    • pp.241-248
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    • 1995
  • Fa SI(Sysrem Intergration)분야에 있어서 PLC(Programmable Logic Controller)와 컴퓨터간의 접속은 필수 불가결한 요소기술로 자리잡고 있으며, 이러한 기술변화에 맞춰서 기존 유니트의 기술적 발전뿐 아니라 타 유니트와 접속등의 네트워킹에 관련된 내용이 하드웨어, 소트프웨어적으로 발전되고 있는 추세이다. 시스템통합을 하기 위해서는 기본적으로 PLC Networking을 하드웨어, 소프트웨어적으로 수행하여야 하나, 많은 연구들이 PLC 통신 유니트의 기술적 향상 및 표준화에 대한 부분으로 되어왔었다. 본 논문은 정보시스템을 구축할 때 PLC에서 처리하여야 하는 데이터, 혹은 컴퓨터와 송수신 받아야 하는 자료들에 대한 내용과 이들 자료를 PLC 내부에서 처리하는 방법론에 대해 기술코자 한다. 일반적인 Interface 방법으로 접점연결(Point to Point Connection)과 컴퓨터링크유니트에 대한 내용을 파악해보고, 설비고장진단 및 이상발생에 대한 추적이 가능하도록 PLC Memory내에 PLC접점데이타를 직접접근방식(Direct Accssing Method)과 간접접근방식 (Indirect Accssing Method)으로 구분하고, 간접접근방식을 요소(Element), 동작(Event)에 의한 방법론을 이용하여 PLC DATA를 처리토록 하는 내용을 설명하고자 한다.

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Development of the Jini Surrogate-based Broadband PLC Home Controller (Jini Surrogate에 기반한 광대역 PLC 홈 제어기 개발)

  • Kim Hee-Sun;Lee Chang-Goo
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.1
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    • pp.1-8
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    • 2006
  • The home network system guarantees families a safe, economical, socially integrated and healthy life by using information appliances. And it provides a family with domestic safety, control of instruments, controllable energy and health monitoring by connecting to home appliances. This study designs the broadband PLC home controller using broadband PLC(Power Line Communication) technology which can save much cost at a network infrastructure by using the existing power line at home. The broadband PLC home controller consists of the broadband PLC module, the embedded main controller module and I/O module. The broadband PLC home controller can control various domestic appliances such as an auto door-lock, a boiler, an oven, etc., because it has various I/O specifications. In this study, selected home network middleware for the broadband PLC home controller is Jini surrogate using Jini technology designed by means of access to easily a home network system without a limitation of the devices. And a client application program is supported java servlet program to manage and monitor the broadband PLC home controller via web browser of a PC or a PDA, etc. Finally, for an application, we implemented and tested a home security system using one broadband PLC home controller.

Improved transient performance of mechanical parking facilities through simultaneous PLC and inverter control (PLC와 인버터의 동시 제어를 통한 기계식 주차설비의 과도 상태 성능 향상)

  • Kim, Chang-Young;Lee, Kyo-Beum
    • Journal of IKEEE
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    • v.25 no.1
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    • pp.116-127
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    • 2021
  • In this paper, we propose simultaneous control which improve in transient state performance of mechanical parking facilities through simultaneous control of PLC and inverter. In conventional mechanical parking facilities, it is controlled only by PLC, and it is more likely to generate over-currents in induction motors, and the ride comfort is reduced due to wear and damage caused by friction on the brake pads, and the life is shortened. To improve this problems the application of control techniques through simultaneous control of PLC and inverter prevents over-currents in induction motors, protects brake pads, improves ride comfort, increases control and ensures safety. We verify its validity by applying the proposed control method via simultaneous control of PLC and inverter to a mechanical parking facility.

PLC 기반의 제어시스템 취약점 분석 방법

  • Kim, Dongwook;Min, Byunggil;Park, Hyun-Dong;Park, Sangwoo
    • Review of KIISC
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    • v.25 no.5
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    • pp.26-36
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    • 2015
  • PLC(Programmable Logic Controller)는 기반시설 운영 현장의 다양한 환경을 견딜 수 있도록 설계된 소규모 산업용 컴퓨터로써, 많은 제어시스템에서 사용되고 있다. 과거의 PLC가 장치 제어를 위한 목적으로 제한된 필수 프로그램만을 사용하였다. 하지만 최근의 PLC는 ethernet 등의 네트워크를 기반으로 다양한 IT 기술들이 적용되고 있다. PLC 기반의 제어시스템은 운영자 및 관리자에게 편의성을 제공하지만 여러 보안 취약점들이 내재되어 있을 수 있다. 취약점들이 공격자에게 노출되어 사이버 위협을 받을 경우, 심각한 보안 사고를 일으킬 수 있으므로, 이러한 취약점들을 찾고 보안 대책을 마련하여 적용하는 것이 필요하다. 그러나 PLC의 특성 및 운용 환경 등이 IT 장비들과는 상이한 점이 있어 IT 장비들을 위한 취약점 분석 방법을 그대로 PLC에 적용하는 것은 한계가 있다. 따라서, 본 논문에서는 PLC의 특성 및 운용 환경 등을 고려한 PLC 취약점 분석 방법에 대해서 제안하고자 한다.

Auto-Generation of Diagnosis Program of PLC-based Automobile Body Assembly Line for Safety Monitoring (PLC기반 차체조립라인의 안전감시를 위한 진단프로그램 생성에 관한 연구)

  • Park, Chang-Mok
    • Journal of the Korea Safety Management & Science
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    • v.12 no.2
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    • pp.65-73
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    • 2010
  • In an automated industry PLC plays a central role to control the manufacturing system. Therefore, fault free operation of PLC controlled manufacturing system is essential in order to maximize a firm's productivity. On the contrary, distributed nature of manufacturing system and growing complexity of the PLC programs presented a challenging task of designing a rapid fault finding system for an uninterrupted process operation. Hence, designing an intelligent monitoring, and diagnosis system is needed for smooth functioning of the operation process. In this paper, we propose a method to continuously acquire a stream of PLC signal data from the normal operational PLC-based manufacturing system and to generate diagnosis model from the observed PLC signal data. Consequently, the generated diagnosis model is used for distinguish the possible abnormalities of manufacturing system. To verify the proposed method, we provided a suitable case study of an assembly line.

Activation of Phospholipase Cγ by Nitric Oxide in Choriocarcinoma Cell Line, BeWo Cells (Choriocarcinoma 세포주 BeWo 세포에서 nitric oxide에 의한 phospholipase Cγ 의 활성)

  • 차문석;곽종영
    • Journal of Life Science
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    • v.13 no.6
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    • pp.849-855
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    • 2003
  • Nitric oxide (NO) plays an important role as a signaling molecule in the proliferation of placenta trophoblasts. In this study, we investigated the effect of NO on the activation of phospholipase C (PLC) in BeWo cells, choriocar-cinoma cell line. Sodium nitroprusside (SNP), an agent to produce NO spontaneously in cells, alone increased $[^3H]$ thymidine incorporation of BeWo cells, indicating NO stimulates proliferation of the cells. NO-induced proliferation of BeWo cells was blocked by U73122, an inhibitor of PLC, suggesting that NO-induced PLC activation is involved in the cell proliferation. NO also stimulated extracellular signal-regulated kinase (ERK) in BeWo cells, indicated by increased phosphorylation of ERK1/2 in Western blotting using anti-phospho-ERK1/2 antibody. NO-induced phos-phorylation of ERK1/2 was not abrogated by U73122. $PLC\gamma_1$l but not$PLC\gamma_2$ was tyrosine phosphorylated by SNP in immunoprecipitation assay using anti-$PLC\gamma_1$/$PLC\gamma_2$ antibodies, and SNP-induced phosphorylation of $PLC\gamma_1$ was abrogated by pre-treatment of cells with genistein and PD98059, indicating that NO induced-phosphorylation of $PLC\gamma_1$ is mediated by ERK. These results suggest that NO stimulates the proliferation of BeWo cells through ERK and $PLC\gamma_1$.

Development of PLC by using micro controller for the distributed fire alarm system (마이크로 콘트롤러를 이용한 분산형 방재 시스템용 중계기 개발)

  • Han, Kyong-Ho;Lee, Ki-Sik;Hwang, Seok-Yong;Kim, Jong-Chol
    • Proceedings of the KIEE Conference
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    • pp.1243-1247
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    • 1996
  • In this paper, a small PLC system is designed and developed for the distributed building control and fire control system. It uses 8031, a 8-bit micro controller from Intel Inc. The size of the PLC is $7cm{\times}8cm$ and the PLC can accept 4 sensor inputs and drive 4 relay outputs, which operates at 24V. Multiple access of PLC by one host computer is implemented by assigning a unique 10 to each PLC, which ranges from 0 to 126. The operation starts by sending a command packet from host computer to a PLC and the PLC of the same 10 fetches the command packet by comparing the first byte of the command packet with its own 10. The PLC is programmed to perform a various functions and the function is selected by the content of the command byte, which is the second byte of the command packet. The third byte, which is the last byte, is a checksum byte. The checksum byte is the sum of the first byte and the second byte and is used to detect the communication error. Depending on the content of the command byte, PLC performs the desired function and returns the response packet back to the host computer. The response packet is also a three-byte packet, 10 byte, response byte and checksum byte. For the independent operation of PLC without being controlled by the host computer, variable length RULE data packet is sent to PLC. In case the communication line is broken, the PLC perform the independent operation by referencing the RULE data. The applicable areas are; building automation system, distributed factory automation, measurement of temperature of toxic or dangerous area.

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