• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1152-1156
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• 2003

For pneumatic valve system control, we need a serial data transmission system with high speed and reliability for information interchange between main computer and I/O devices. This paper presents a set of design techniques for a data communication system that is mainly used for pneumatic valve system control. For this purpose, we first designed hardware modules for an interface between central control module and local node that handles the operation of solenoid control valves. in addition, we developed a communication protocol for construction of rs-485 based multi-drop network and this protocol is basically designed with a kind of polling technique. Finally we evaluated performance of the developed system. the field test results show that, even under high noise environment, the data transmission of 375kbps rate is possible up to 1,500meter without using repeater. In addition, the system developed in this research is easily to be extended for a communication network because of its modular structure.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.691-694
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• 2003

This paper describes how to use Profibus networks to support real-time industrial communications, that is, how to ensure the transmission of real-time messages within a maximum bound time. Profibus is based on a simplified timed token protocol, which is a well-proved solution for the real-time communication systems. However, Profibus differs from the timed token protocol, thus the usual timed token protocol has to be modified in order to be applied in Profibus. In fact, the real-time solutions for networks based on the timed token protocol rely on the possibility of allocating specific bandwidth for the real-time traffic. This means that a minimum amount of time to transmit the real-time messages is always guaranteed whenever each token is arrived. In other words, with the Profibus protocol, at least, one real-time message should be transmitted per every token visit in the worst case. It is required to control medium access properly to satisfy the message deadlines. In this paper, we have presented how to obtain the optimal network parameter for the Profibus protocol. The selected network parameter is valid regardless of the behavior of asynchronous messages.

• Journal of the Korea Convergence Society
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• v.11 no.11
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• pp.55-61
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• 2020

The communication issues expected for SMEs are that 1) IT systems are not easy to connect, 2) data collection and integration by heterogeneous systems are difficult, and 3) various fieldbuses and protocols make interfaces difficult. Usually, SMEs often have automation built before the introduction of smart factories. It is necessary to provide communication technology such as Sensing to meet the heterogeneous system level with the old aged sensors in the automation equipment and communication network of SMEs. We will consider how to improve the network interface before applying the latest network technology at the time of preparation using PI.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.945-947
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• 1999

첨단의 자동화 시스템을 구축하기 위해서는 각 필드기기에서 생산되는 정보들을 적절한 형태로 가공하여 적시에 필요한 공정으로 제공하여 줄 수 있는 지능형 센서 및 필드기기의 도입이 필요하다. 이러한 필드기기들이 유기적으로 정보를 교환하고 공유하기 위해서는 통신망 시스템을 구축할 필요가 있다. 필드버스는 자동화 및 분산 제어 시스템의 컴퓨터 통신망 계층구조에서 최하위 계층 기기들 간에 실시간 통신을 제공하는 산업용 통신망이다. 본 연구에서는 통신용 프로세서인 Mc68360을 기반으로 하여 필드버스의 일종인 Profibus의 물리계층과 데이터링크계층 프로토콜을 구현하였다. 물리계층은 프로세서의 UART 통신 기능과 RS-485칩을 사용하여 구현하고, 데이터링크계층 프로토콜은 프레임 분석과 송수신, 에러처리, 흐름제어, 매체접속권한 관리 등의 기능을 소프트웨어로 구현하였다. 또한 지능형 센서 본래의 목적중의 하나인 원격관리 기능을 위하여 각 필드기기의 노드 주소, 타이머 값 등의 통신 파라미터를 원격 마스터에서 설정할 수 있도록 관리계층의 기능을 추가하였다. 본 연구에서는 각각 하나의 노드기능을 담당하는 여러 개의 보드들로 구성된 testbed를 구축하고, 다양한 통신환경에서 초기화, 정상, 비정상 상태 등의 동작을 실험하였으며, 이를 통하여 지능형 센서용 필드버스의 데이터링크계층 프로토콜이 정상적으로 동작됨을 확인하였다.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.4
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• pp.313-319
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• 2000

As the interest of flexible manufacturing systems and computer integrated manufacturing systems increase, the distribution of centralized control systems using industrial control networks is getting more attention. In this paper, we investigate the rate-based traffic control of industrial control networks to improve the performance regarding the throughput, fairness, and error rates. Especially, we consider the protocol of Lon-$Works^{(TM)}$ which consists of all OSI 7-layers and supports various communication media at a low cost. Basically, the proposed rate-based traffic control system is closed loop by utilizing the feedback channel errors, which shows improved performance when compared with other industrial control networks commonly operated in open loop. To this end, an additional network node called monitoring node is introduced to check the channel status without increasing the channel load. The Proposed control loop is in effect whenever the feedback channel error becomes greater than an admittable value. We demonstrate the improved performance of the controlled network system in view of throughput and fairness measures by implementing the lab-scale network system based on LonWorks and through the experimentation upon it.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.1
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• pp.113-122
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• 1998

This paper presents an implementation method of Profibus interface software using FMS(Fieldbus Message Specification). The Profibus interface software is implemented on PC which is widely used as an industrial computer as well as a commercial embedded controller called IUC(Intelligent Universal Controller). In order to enable the Profibus interface software to handle many application tasks and communication services, two kinds of real-time/multi-tasking operating system, OS-9 and CTask, are utilized. We also develop an experimental model of Profibus-based automation system, and evaluate the performance of the Profibus network. Through experiments, the user layer level message latency is measured with respect to the change of message length, message generation interval and TRT(Target Rotation Time). The results of experiment are compared with those of a simulation model which comprises only the physical and data link layers of Profibus. The results of this study shows that the message latency in the user layer level occupies fairly a large part of the total message latency.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.4
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• pp.326-333
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• 2001

This paper focuses on a method to connect mobile devices such as mobile robot. Automated Guided Vehicle (AGV) and Unmanned Container Transporter(UCT) to a fieldbus. In this paper, the IEEE 802.11 wireless LAN is used to extend a Profibus network for the mobile devices. In order to integrate these two networks, a gateway is developed using two threads and an internal buffer. Furthermore, a polling algorithm is applied at the gateway in order to satisfy real-time requirements on data communication, Finally, the performance measures such as data latency and throughput are experimentally evaluated on a wirelessly-extended Profibus network. The results shows the feasibility of the wireless extension of Profilbus for various mobile device.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.7
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• pp.2874-2891
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• 2016

Due to its potential, the Internet of Things (IoT) begins to be used in the industrial field. Nevertheless, although the concept called the Industrial Internet of Things does not know a widely accepted definition, it is based on the existing technology, and introduces the IoT in the industrial environment through the compliance with specific additional requirements and by integrating various fieldbuses with distinctive features, from the real-time point of view. The aim of this paper is to propose a practical architecture for the Industrial Internet of Things. The proposed architecture is designed around the Data Distribution Service for Real Time System (DDS) middleware protocol, and it is organized on four levels. Between these levels, it is defined standard interface, and they can be developed independently. For this reason, the architecture is scalable because at the middleware level, the DDS can be replaced by other middleware systems. At the final, it is performed a comparison between several middleware systems used in the proposed architecture.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.4
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• pp.436-445
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• 2011

As automation systems become intelligent and autonomous for productibility, industrial networks (fieldbuses) and network-based devices are essential components of intelligent manufacturing systems. However, there are obstacles for the wide acceptance of the network-based devices such as smart sensor and network-based actuator. First, there exist numerous fieldbus protocols that a network-based device should be able to support. Second, the whole network-based device has to be replaced when only the sensor of the module fails. In order to overcome these obstacles, a smart sensor/actuator is implemented as two units; one responsible for network communication and the other for sensor/actuator operations using IEEE 1451.0 standard. This paper presents a structure of the 1451.0-based smart sensor with multiple connectivity function designed by CANopen.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.6
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• pp.533-541
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• 2017

Recently, with the adoption of modern computing and communication technologies, manufacturing systems have become more autonomous and intelligent. Thus, as the number of field devices with smart sensors also increase, the need for an integrated management of such devices becomes essential. This paper proposes a smart encoder architecture that integrates the position sensing function with CANopen connectivity. In addition, an integrated system is proposed to simultaneously control and monitor multiple encoders over the Controller Area Network (CAN) fieldbus network. We evaluated the performance and functionalities of the proposed system by comparative experiments with commercial CANopen smart encoders using a CANopen conformance test.