• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.642-649
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• 2018

The Modbus protocol is the most widely used protocol for connecting multiple slave control units (SCUs) in the master control unit. However, the Modbus protocol does not identify which SCU response message corresponds to the service request message. Therefore, when using the Modbus protocol, one service request message can be transmitted after processing the previous message. In this paper, we propose a Modbus application protocol with an index code and a service code to solve the problem. As a result of experimentation, it is possible to transmit the next service request message without processing the previous service request message. And when a communications error occurs, it is possible to identify what type of error occurred using an error detection algorithm. Also, with simultaneous multiple service requests, the proposed protocol can improve processing time by about 66.2%, compared to the original Modbus protocol.

• Review of KIISC
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• v.25 no.5
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• pp.37-44
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• 2015

산업제어 시스템의 통신 프로토콜 중 하나인 MODBUS/TCP는 오늘날 산업체에서 높은 점유율로 사용되고 있다. 단순한 구조로 다양한 기능을 가지고 있어 "hard real system"에서 주로 사용되고 있는 MODBUS/TCP의 보안 적용 방안 또한 많은 연구로 진행되어 왔다. DNP3, SSL, SCTP와 같은 프로토콜을 연동하거나 공개키를 이용한 전자서명 적용 등의 방법이 대표적인 MODBUS/TCP의 보안 방법은 충분한 메모리 크기, 고속 공개키 연산을 위한 하드웨어 가속기 등을 요구로 한다. 하지만 I/O 디바이스 등 열악한 환경에 이는 부담스러운 요소로 작용될 수 있다. 따라서, 본 논문에서는 이러한 열악한 환경에서 안전한 MODBUS/TCP 통신과 기존의 MODBUS/TCP와의 호환성을 고려한 보안 적용 방안을 소개한다. 또한 측정한 결과를 통해 본 논문에서 제시하는 E-ModbusSec가 "hard real system"에서 충분히 제 역할을 수행할 수 있음을 보이고자 한다.

• Journal of Navigation and Port Research
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• v.41 no.6
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• pp.395-400
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• 2017

As a serial communications protocol, Modbus has become a practically standard communication protocol and is now a commonly available means of connecting industrial electronic devices. Therefore, all devices can be connected using the Modbus protocol with the measurement and remote control on ships, buildings, trains, airplanes and more. The existing Modbus that has been used is based on serial communication. Modbus TCP uses Ethernet communication based on TCP / IP which is the most widely used Internet protocol today; so, it is faster than serial communication and can be connected to the Internet of Things. In this paper, we designed an algorithm to control LED lighting in a wireless Wi-Fi environment using the Modbus TCP communication protocol, and designed and implemented a LED controller circuit that can check external environmental factors and control remotely through the integrated management system of a ship. Temperature, humidity, current and illuminance values, which are external environmental factors, are received by the controller through the sensors, and these values are communicated to the ship's integrated management system via the Modbus protocol. The Modbus can be connected to Master devices via TCP communication to monitor temperature, humidity, current, illuminance status and LED output values, and also users can change the RGB value remotely in order to change to the desired color. In addition, in order to confirm the implementation of the controller, we developed a simulated ship management system to monitor the temperature, humidity, current and illumination conditions, and change the LED color of the controller by changing the RGB value remotely.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.1054-1057
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• 2015

Real time processing is important in the industrial field. In this paper, we implement for Modbus/RTU(Remote Terminal Unit) protocol using LabVIEW based on serial communication. In other to obtain the experimental data from torque sense and voltage/current meter, Modbus/RTU protocol is implemented by LabVIEW tool. Mechanical loss can be calculated by torque, RPM, voltage, and current. Source code consist of panel and block diagram. We confirmed these source code can be applied in industrial field.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.318-321
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• 2017

인더스트리4.0 시대의 도래로 첨단의 자동화 시스템을 구축하기 위해서는 각 장비들의 정보를 수집,분석,가공,저장 등의 작업을 수행하여야 하며 각 장비들은 통신을 통하여 모든 정보를 통합할 수 있게 하며 통신 시스템은 인더스트리4.0의 시대의 핵심 기술이라 할 수 있다 본 연구에서는 산업 표준프로토콜로 자리잡고 있는 MODBUS 프로토콜을 활용하여 통신 제어를 제안한다. 각 지원되는 기능들을 알아보고 각 프로토콜 파싱기법과 에러처리를 알아보고 MODBUS프로토콜을 만들어 통신제어가 가능함을 확인하였다.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.05a
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• pp.22-27
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• 2000

This Paper decribes a monitoring system using Modbus protocol and RS485 interface applied in many industrial field. We developed hardware to receive alanlog sensor output and monitoring program to communicate with hardware and carried out experiment with potentiometer for plan sensor, . Through online communication between Master and Slaves we convinced the usage of this systems. Also plant data file that saved in Excel format is convenient in writing various typs of documents.

• Journal of the Korea Society of Computer and Information
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• v.25 no.6
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• pp.1-8
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• 2020

Communication between system modules is applied using the Modbus protocol in industrial sites including smart factories, industrial drones, building energy management systems, PLCs, ships, trains, and airplanes. The existing Modbus was used for serial communication, but the recent Modbus protocol is used for TCP/IP communication.The Modbus protocol supports RTU, TCP and ASCII, and implements and uses protocols in embedded systems. However, the transmission I/O devices for RTU, TCP, and ASCII-based protocols may differ. For example, RTU and ASCII communications transmit on a serial-based communication protocol, but in some cases, Ethernet TCP/IP transmission is required. In particular, since the C language (object-oriented) is used in embedded systems, the complexity of source code related to I/O registers increases. In this study, we designed software that can logically separate I/O functions from embedded devices, and designed the execution logic of each instance requiring I/O processing through a delegate class instance with Modbus RTU, TCP, and ASCII protocol generation. We designed and experimented with software that can separate communication I/O processing and logical execution logic for each instance.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.780-783
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• 2015

MODBUS/TCP는 단순하며 기능이 다양해 산업제어시스템에서 높은 점유율로 사용되는 통신 프로토콜이다. 오랜 시간 많은 사용과 더불어 안전한 MODBUS/TCP를 위한 연구 또한 많이 이루어졌지만, 이는 공개키 적용, SSL과 같은 라이브러리 연동, SCTP와 연동한 Hybrid 형식 등이 대부분이다. hard real system에서 주로 사용되는 MODBUS/TCP는 무엇보다 정해진 timeout 시간 내에 통신이 이루어지도록 해야 한다. 따라서 앞서 말한 방법은 하드웨어 가속기, 충분한 메모리 요구량 등의 문제가 따른다. 본 논문은 hard real system의 산업제어시스템에서 요구하는 timeout 시간을 충족하며 안전한 통신을 제공하는 보안 적용 방안을 소개하며 실험의 결과를 통해 실질적으로 효과적인 대안임을 보이고자 한다.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.3
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• pp.292-301
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• 2014

This paper describes development of distributed type independent electro-hydraulic ballast valve remote control system with diagnostic function based on fuzzy inference using redundant Modbus communication and ethernet Modbus TCP/IP. Diagnostic function estimate degradation of system components and diagnose system faults, which results in shortage of fault maintenance time and improvement of system safety. Slave devices which control each valve and master device which command, monitor and diagnose slave system are developed. Slave devices are connected to master device with redundant Modbus networks and master device is connected to ship's integrated control system with Modbus TCP/IP. Also this paper describes development of simulator to test and confirm whether developed system can be integrated with ship's integrated control and monitoring system.

• Journal of IKEEE
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• v.19 no.3
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• pp.311-318
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• 2015

This dissertation proposes method for development technology of voice and SMS(Short Message Service) alarming system based on modbus protocol. The proposed technology is composed of the following 3 stages; hardware development based on microprocessor, development of input and output driver for modem, mp3 decoder, making modbus protocol stack. In the stage of hardware development based on microprocessor, we develop hardware which receives alarm from modbus master and transmit sms message, play mp3. In the stage of development of input / ouput device driver such as modem, mp3 decoder, we develop program which control each devices. In the stage of making modbus protocol stack, voice and sms alarm system is made for receiving alarm via modbus protocol. To evaluate performance of proposed technology, we issued alarm to voice and sms alarming system on purpose. As a result, response speed of detecting alarm was 10.7ms, communication distance was 1.2Km, operating temperature was from $-25^{\circ}C$ to $70^{\circ}C$, we confirmed supporting modbus protocol. And we verified that proposed voice and sms alarming system in the thesis has a performance to be used as an industrial building alarming system.