Profibus-DP Protocol Research Articles

Use of Modbus RTU, Profibus DP and HTTP Protocol for AC Motor Control

This work is part of a project to develop a test stand using a network simulator of ship traffic control and physical models of ship propulsion system components. The lab station is designed to allow control of the engine by three methods. Web-based control, slave-level control as well as master-level control. The components of the lab bench and the various blocks used in the TIA Portal program are described. The article deals with the application of Internet 4.0 to AC motor control. In order to be able to synthesize a laboratory workstation to enable the control capabilities of Internet 4.0, an idea diagram is described. The Profibus DP protocol was used to connect the I/O module to the PLC, which made it possible to control the operation of the motor directly from the module through the PLC connected to the inverter by the Modbus RTU protocol. In order to implement an experimental Internet 4.0 workstation, it was also necessary to add remote control using the HTTP protocol and design a website. All the above-mentioned protocols were briefly discussed and implemented in the TIA Portal environment. Also described is the idea and operation of a program written in the LAD language, which is designed to control an AC motor from three different devices: PLC, I/O module and PC via a web page. In the construction of the program, the MB_COMM_LOAD and MB_MASTER blocks dealing with communication and control with the inverter were used, as well as the WWW block used to communicate the controller with the website. The operation of the software was verified from the level of two devices, the I/O module and the website, including its optimization for the correct operation of the entire system as shown in the graph of the change in the value of the AC motor speed control word. In the final part of the work, an analysis of the suitability and validity of using such a system in industry was carried out.

Automatic Diagnosis for Profibus Networks

This research proposes the use of intelligent systems to diagnose industrial network communication via Profibus DP Protocol. These diagnostics are based on the information provided by the physical, data link and user layers from the Profibus DP. In order to analyze the physical layer, an artificial neural network first analyzes signal samples transmitted through industrial network. Moreover, some diagnostics can be acquired by using an expert system that analyzes frames which are transmitted by the data link layer. Finally, this research proposes a fuzzy system, which indicates to the user an ideal value to the target rotation time variable. The project was validated by data obtained from concrete Profibus protocol and by some synthetic data. The results were satisfactory, proving the great strength and versatility that intelligent computer systems have when applied to the outlined purposes in this work.

Implementación de un dispositivo pasivo para una red Profibus-DP, basado en microcontrolador

Se presenta el desarrollo de una estación pasiva para entradas y salidas de propósito general, con capacidad de comunicación mediante el protocolo Profibus-DP. La implementación se basa en un microcontrolador STM32, respetando las especificaciones de las capas física y de enlace de datos definidas para el protocolo. Se describe la arquitectura hardware y software de la estación pasiva, así como las pruebas a las que fue sometida para verificar su funcionamiento. Tales pruebas involucran equipos industriales de reconocidos fabricantes, para demostrar la capacidad de interoperabilidad del dispositivo.

Research on Continuous Emission Monitoring System in Thermal Power Plant

The system aims to collect reliable emission data in real time, provide the operator with real-time emission parameters, and guide the optimization of unit operation and control of pollutants in flue gas emissions. One kind of continuous emission monitoring system is designed based on PROFIBUS-DP protocol in power plant, the architecture of system is presented and the principle is described in detail.

Data Transmission Mode of a Small-Scale, Real-Time Industry Control Network

MAC protocol of bus control network has important influence on its real-time feature. Combining Profibus-DP protocol and Token Bus protocol, a new bus model suitable for small-scaled control system is put forward. Under the principle that follows a control network whole balance, the LAS and GAPL maintenance process in token passing mode and master-slave polling process in data exchange mode of Profibus-DP are discarded. The basic cutting thought of this bus model is summarized; its concrete realization is illustrated in detail, theoretical maximal value of message transmission time and actual test result are presented. The experiment result shows the system’s real-time characteristic is improved, and come to the expectant result.

Hybrid wired/wireless implementations of Profibus DP: a feasibility study based on Ethernet and Bluetooth

The communication networks used by factory automation systems are beginning to employ solutions that, until recently, were used in different fields. In particular, at the lowest level of automation, where, typically, real time communication between controllers and sensors/actuators is required, both Ethernet and wireless networks are becoming solutions of interest. However, the introduction of such technologies poses severe problems in terms of compatibility with already implanted fieldbuses. It is thus highly likely that, in the near future, modifications of the existing fieldbus standards will be considered, in order to accommodate hybrid network configurations, where communications take place on both Ethernet/wireless segments. This paper considers a very popular fieldbus protocol, Profibus DP, and analyzes the possibility of implementing it on hybrid wired/wireless networks, based on Ethernet and Bluetooth, respectively. Two basic configurations are analyzed and, after a description of how the Profibus DP protocol functions could be mapped on both Ethernet and Bluetooth, a theoretical study of the network behavior is carried out. Finally, simulations results are shown, which validate the theoretical analysis and show the soundness of the proposed protocol stack for industrial applications.