• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.741-744
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• 1990

This paper deals with the implementation of the IEEE 802.4 token passing bus protocol which is the world standard for LAN protocol. We are design station adaptor using MC68824 for data link layer, MC68194 for physical layer, and implemented by IEEE 802.4 and 802.2 type 3. We made three station adaptor and its performance is experimented.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.28B no.5
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• pp.404-410
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• 1991

In this paper,a network interface unit of token-passing bus network and its driving software are implemented based on Mini-MAP. This network interface unit performs the function of MAC layer which is responsible for transmission and reception of frames as well as the management of logical ring. The driving software performs the management of data buffer and the report of errors, if ocoured, to the higher layer. Motorola MC68824 of is used as a TBC(Token Bus Controller) and Intel80186 as a CPU for network interface unit. The operation of network interface unit is verified by self-test which checks the functioning of TBC and CPU. In addition each module of driving software is tested to check the functions regarding transmission and reception of frames.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.3
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• pp.22-31
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• 1989

In this paper, we analyze the performance of the IEEE 802.4 token passing bus protocol through a simulation model of the protocol. In order to analyze performance of the protocol in the initialization, transition and fault recovery states as well as in the steady state, the protocol functions are divided into five processes each of which can effectively simulate protocol behaviors according to the variations of protocol parameters. From the simulation study, we obtain protocol parameters which severely influence the protocol performance and find out that proper selection of the protocol parameter values for token passing is very important to obtain good performance of the protocol when the priority scheme is used.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.10
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• pp.882-890
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• 2001

The data link layer of Foundation Fieldbus is operated on the basis of scheduling and token-passing disciplines. This paper presents a network design method of Foundation Fieldbus using a bandwidth allocation scheme. Fieldbus traffic consists of periodic data and sporadically generated time-critical and time-available data. The bandwidth allocation scheme schedules the transmission of periodic data. Time-critical and time-available data are transmitted via a token-passing service. The validity of this bandwidth allocation scheme is determined using an experimental model of a network system. The results obtained from the experimental model show that the proposed scheme restricts the delay of both periodic and time-critical data to a pre-specified bound. The proposed bandwidth allocation scheme also fully utilizes the bandwidth resource of the network system.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.12
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• pp.1055-1064
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• 2003

In many automated systems, such as manufacturing systems and process plants, a fieldbus is a very important component for the exchange of various and sometimes crucial information. Some of the information has a tendency to rapidly lose its value as time elapses after its creation. Such information or data is called real-time data that includes sensor values and control commands. In order to deliver these data in time, the fieldbus network should be tailored to have short delay with respect to the individual time limit of various data. Fine-tuning the network for a given traffic requires the knowledge on the relationship between the protocol parameters such as timer values and the performance measure such as network delay. This paper presents a mathematical performance model to calculate communication delays of the Profibus-FMS network when the timer value and the traffic characteristics are given.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.426-429
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• 2002

The data link layer (DLL) of Foundation Fieldbus (FF) includes both token-passing and scheduling services. Periodic data are transmitted via the scheduling service, while time-critical and time-available data are transmitted via the token-passing service. This study developed a network interface board that implements the DLL of FF. Using the network interface board, this study experimentally evaluates the delay performance of the DLL of FF. This study measured the delay performance with respect to the change of the DLL parameters of FF, and investigated the relationship between the DLL parameters and network performance. The study also compared the experimental results with the results obtained from an analytical model.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.926-929
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• 1988

In this paper, the implementation of NIU (Network Interface Unit) for Token Passing Bus network is studied. The network is based on the IEEE 802.4 standard, which is the basis of MAP. IBM-PC is chosen as host station. The structure of the network and NIU is investigated and the implementation is illustrated. The logical ring constructed following the standard. Transmission and reception of data are tested. The experimental results are referred.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.609-611
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• 1998

In this paper, a method for the efficient implementation of the control network for a distributed control system (DCS) is proposed. The proposed method focuses on the real-time property and the low networking cost of a control network. It suggests a new network architecture combining the IEEE 802.4 token-passing bus access method and the IEEE 802.3 physical layer. For this purpose, a new interface, a physical layer service translator is introduced. A control network using this method is implemented and applied to a DCS.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1420-1423
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• 1996

This paper presents the implementation of network for automation using fieldbus. The RS-485 and twisted pair are used in layer 1 and medium, respectively. We implement FDL(Fieldbus Datalink Layer) using C-language and use token-bus network. The network consists of polling system and token passing system. The amount of transmitted data frames is evaluated with various transmission speeds that affect the system stability.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.618-622
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• 1990

In this study LLC and MAC program, which is the base of the communication software, is implemented. This program is tested in the MAP board for IBM PC. The LLC is of class 3, which provides the services of type 1 and 3. The MAC uses the Token Passing Bus Access Method of IEEE 802.4 standard. The LLC is implemented in C language, and MAC in C language and 80186 assembly language. MAC program takes advantage of MC 68824 which is the token bus controller produced by Motorola.