• International Journal of Advanced Culture Technology
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• v.11 no.1
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• pp.395-402
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• 2023

The implementation of a hybrid network utilizing Power Line Communication (PLC) and Wi-Fi technologies has been demonstrated to improve signal strength and coverage in areas with poor connectivity due to internet shadow areas. In this study we strategically positioned Wi-Fi relays and utilized the capabilities of PLC technology to significantly improve signal strength and coverage in areas with poor connectivity. We also analyzed the effects of metallic obstacles on Wi-Fi signal propagation and proposed a solution to strengthen the signal enough to pass through them. Our experiment demonstrated the feasibility and potential of using this hybrid network in industrial scenarios for real-time data transmission. Overall, the results suggest that the use of PLC and Wi-Fi hybrid networks can be a cost-effective and efficient solution for overcoming internet connectivity challenges and has the potential to provide high-speed internet access to areas with unreliable signals.

• Journal of the Korea Society of Computer and Information
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• v.25 no.6
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• pp.17-23
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• 2020

In this paper, collecting real-time data frames that occur during RS232 communication between an HMI and PLC of automation equipment by sniffing real-time information data frames through MCU without modification of the HMI or PLC, a method is proposed that allows users to collect data without being dependent on the modification of PLC and HMI systems. The user collects necessary information from the sniffing data through the parsing operation, and the original communication interface is maintained by transmitting the corresponding sniffing frame to the destination. The MCU's UART communication interface circuit is physically designed according to the RS232 communication standard, and this additionally improves efficiency more so than an interrupt-based system by using the DMA device inside the MCU. In addition, the data frame IO operation is performed by logically separating the work of the DMA interrupt service routine from the work of the main thread using the circular queue. Through this method, the user receives the sniffing data frame between the HMI and PLC in RS232 format, and the frame transfer between PLC and HMI arrives normally at the original destination. By sniffing the data frame without further modification of the PLC and HMI, it can be confirmed that it arrives at the user system normally.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.11
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• pp.51-55
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• 2007

Generally, PLC (Power Line Communication) based home automation devices such as wall switch, walt socket, gas controller, etc, must maintain wake-up status at all time to control other electronic devices and monitor their on/off status whether they are in service or not. In order to reduce the unnecessary energy consumption during the standby mode, the new power-saving PLC 2 ports wall switch has been developed, separating PLC communication part and controller part and introducing sleep mode. In addition, to expand life cycle of PLC product and to reduce the rate of product failure in active mode, the instant controlling method in controlling process is adopted instead of the maintenance controlling method. In comparison to the earlier model, the new 2 ports PLC wall switch has reduced power by 0.95[W] less in standby mode and 3.2[W] less in active mode than the previous one.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.1
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• pp.65-75
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• 2011

Power Line Communication (PLC) is a system for carrying data on a conductor used for electric power transmission. Recently, PLC has received much attention due to connection efficiency and possibility of extension. It can be used for not only alternative communication, in which communication line is not sufficient, but also for communication between home appliances. Korea Electronic Power Cooperation (KEPCO) is constructing the system, which automatically collects values of power consumption of every household. Due to the randomness and complicated physical characteristics of PLC protocol (KS X4600-1), it has been believed that the current PLC is secure in the sense that it is hard that an attacker guesses or modifies the value of power consumption. However, we show that the randomness of the protocol is closely related to state of the communication line and thus anyone can easily guess the randomness by checking the state of the communication line. In order to analyze the security of PLC, we study the protocol in detail and show some vulnerability. In addition, we suggest that PLC needs more secure protocol on higher layers. We expect that the study of PLC help in designing more secure protocol as well.

• 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.

• Journal of Korea Game Society
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• v.7 no.1
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• pp.53-58
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• 2007

In this paper, a game control system was constructed, in which a game was controlled by a remote joystick connected with a power line by the power line communication (PLC) method. The structure of the system was that the connection line between the remote joystick and a PC, and the PC and an audio play device was the home power line. And, the communication data rate between them was 2400 bps. The Polling communication technique was used for the PC to read the joystick's control commands, and to send some acoustic informations to the receiver PLC device. A game was programmed, in which an aircraft was moved according to the joystick's left, right, up, and, down direction, and was shooting its missile after the joystick's shooting button was pushed. The communication delay of about 100 msec between them didn't cause any big problem in playing the game.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.476-478
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• 1993

Instead of installing new communication wiring to each house in the apartment house building. the power distribution network. which is already installed in the building. can be use as communication medium. In a safty management, by adoption of power line communication system, at remote we can monitor safty related sensors such as fire, gas leakage, burglar intrusion and emergency call which are located at each house. From this viewpoint, we developed security monitoring system for apartment house building using power lines. Security monitoring system consists of Power Line Communication-Sub Controller (PLC-SC). Power Line Communication-Main Controller (PLC-MC) and Management System (MS). Between a PLC-MC and a PLC-SC, the transmission rate is 1200 bps in power lines and modulation technique is frequency shirt keying (FSK). In between a PLC-MC and a MS, the transmission rate is 1200 bps in communication line (RS-485). As a result of this research. transmission loss is 0.1dB per meter of intrabuilding distribution network. Transmission can be reach in 250 meters. So it is enough to communicate for security monitoring system in apartment house building.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.1
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• pp.43-47
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• 2021

This paper investigates the network throughput of PLC (Power Line Communication) system in the in-building network. The OFDM (Orthogonal Frequency Division Multiplexing) modulation format and adaptive bit loading algorithm is used to minimize the effect of signal loss and noise on transmission performance in the power line channel characterized by frequency selective fading. The network throughput of the PLC system which consists of gateway and CPE（Customer Premise Equipment) PLC modem in the in-building network is measured by network performance measurement tool, iperf and analyzed according to the TCP (Transmission Control Protocol) window size.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1002-1003
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• 2006

Power line communication: PLC which easy to install at anywhere near outlet for electric machine. PLC uses transmission line for voltage of which is 60 Hz. One of the important thing is the processes of adding signal to power line and extracting the signal from power line, another is to choose the strong modulation method which sends signals to long distance without loosing in PLC channel. but PLC channel have very high and variable noise and attenuation and then it is very hard to transmit optimally between the transmitter and the receiver. AWGN, impulse noise and attenuation are created. To overcome the noise and attenuation. Multi-carrier Modulation methods like as OFDM and DMT which divide the channel into many sub-channel are powerful communication methods for PLC. In this paper, PLC channels are simulated for getting BER by Matlab simulink

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.11
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• pp.1109-1117
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• 2017

In this work, a new control module and communication system associated with DSP are proposed to overcome the limitations of the contemporary prevailing PLC-based industrial equipment controller, and the performance of the proposed system was experimentally verified. In the light of this issue, a communication conversion scheme from RS-485 to Modbus, the dominant communication protocol used by PLC, was developed and shown to yield enhanced compatibility between devices. The proposed system allows for ~50％ cost reduction as well as downsizing of the industrial controllers. Furthermore, the design includes 24 V general digital I/O pins, which facilitate partial expansion of inputs and outputs. With Modbus communication implemented in DSP with the RS-485 interface, multi-to-multi communication may also be achieved.