In this paper we present some aspects and methods that were applied during the realization of a subsystem of an electronic railway interlocking system. First, the operation of the special 75 Hz track circuit control s...
详细信息
In this paper we present some aspects and methods that were applied during the realization of a subsystem of an electronic railway interlocking system. First, the operation of the special 75 Hz track circuit control subsystem will be described. Following, the applied description method for the 75 Hz control tasks will be discussed. Finally, an interesting aspect of the development will be shown: the extension of the operating system of the PLC.
The main task of control program loaded in any PLC is to ensure proper functionality of the designed machine or technological line. From the diagnostic and maintenance point of view the same program is to ensure fault...
详细信息
The main task of control program loaded in any PLC is to ensure proper functionality of the designed machine or technological line. From the diagnostic and maintenance point of view the same program is to ensure fault detection, machine status check and machine restart to be done with ease. Such aspects are connected with many items, one of the most important is program structure. Intention of the authors is to present some remarks regarding different program structures, programming aspects, which support users and maintenance to detect and cover faults and stoppages.
In the following article the project of solution of distributed control system is described in which the operating system QNX in the connection with industrial bus CAN and industrial controllers PLC is used. Two ways ...
详细信息
In the following article the project of solution of distributed control system is described in which the operating system QNX in the connection with industrial bus CAN and industrial controllers PLC is used. Two ways of control system project are discussed there. The first one makes use of industrial computers of the PC type and industrial buses with intelligent sensors and actuators, the second project includes in this network also the industrial controllers PLC. With the interconnection of both possibilities we obtain the third solution which provides the advantages of both previous ones what is the high computing capacity of industrial computer and the capability of programmable controller to work in real time.
To design the control of automated systems, the designer must evaluate the performances of various solutions. Our research deals with the evaluation of distributed control architecture. We have chosen Colored Timed Pe...
详细信息
To design the control of automated systems, the designer must evaluate the performances of various solutions. Our research deals with the evaluation of distributed control architecture. We have chosen Colored Timed Petri Nets (CTPN) models for describe behaviors of each equipment of control and we use design/CPN simulation tool to assess response times performance. The aims of this paper are to build various programmablelogic Controller (PLC) behavior models and to select the best according to our needs in performance evaluations. Various approaches for the creation of CTPN models are discussed. Some of them are based on synthesis techniques and some of them are based on an identification technique. Finally, a comparison method is presented. It will allow the designer to choose the right model for the simulation in the evaluation stage.
Romania is not only a country with an important metallurgical tradition. Romania’s metallurgical industry applied all major technology developments short time after or even before other traditional sites. Nowadays a ...
详细信息
Romania is not only a country with an important metallurgical tradition. Romania’s metallurgical industry applied all major technology developments short time after or even before other traditional sites. Nowadays a well-represented industry is looking for up-to-date automation systems. The modernization of the SIDEX’s zinc coating line, using SIEMENS products, shows the ability to use the most advanced automation products and concepts.
Recently, La Papelera del Plata implemented the Paper Machine IT project in zarate, Buenos Aires. The integration of control system with supervisory sensor based systems, actuator systems, PLC systems and drives was c...
详细信息
Recently, La Papelera del Plata implemented the Paper Machine IT project in zarate, Buenos Aires. The integration of control system with supervisory sensor based systems, actuator systems, PLC systems and drives was considered the most important. True system integration requires system level interoperability. ABB has achieved this by offering a wide range of pulp & paper solutions built upon a common system platform. This paper describes how this project was executed and presents the results achieved by La Papelera del Plata paper mill through the application of integrated system solutions, on the Advant Open Control System (OCS) with Master software foundation.
This paper describes a mechanical system with a bouncing ball, it’s parameters, mathematical model and control design process using a programmablelogic controller. This system is very good object for the demonstrati...
详细信息
This paper describes a mechanical system with a bouncing ball, it’s parameters, mathematical model and control design process using a programmablelogic controller. This system is very good object for the demonstration of discrete event control and illustration of the possibilities and constraints of programmable logic controllers.
In the paper a structured synthesis method based on the direct mapping of hierarchical interpreted Petri nets into field programmablelogic is presented. The described methodology is especially useful for designing of...
详细信息
In the paper a structured synthesis method based on the direct mapping of hierarchical interpreted Petri nets into field programmablelogic is presented. The described methodology is especially useful for designing of Industrial Application Specific logiccontrollers (ASLCs) with FPGA. The specification of the reactive system in the form of symbolic, if-then or if-then-else conditional decision rules is transformed into a HDL format that is accepted by standard FPGA simulators and synthesis tools. The Concurrent State Machine model of logic Controller is verified using the well-developed Petri net theory, and then it is translated through automated processes into selected FPGA specification format.
Though the controller landscape is a place of constant change, PLCs have not yet been replaced by PCs. One glance at products released lately shows PLC manufacturers have adapted to threats from PC-based, `open', ...
详细信息
Though the controller landscape is a place of constant change, PLCs have not yet been replaced by PCs. One glance at products released lately shows PLC manufacturers have adapted to threats from PC-based, `open', and embedded control. New form factors exploit economies of size. Functions previously reserved for large PLCs are routinely found in micro units. Sometimes the controller just looks like a PLC, inside it really a PC.
There is an ironic, but very common occurrence in factories today. The Information Systems (IS) manager can, from his desk, tell whether any printer worldwide is out of paper - but he cannot tell if the production mac...
详细信息
There is an ironic, but very common occurrence in factories today. The Information Systems (IS) manager can, from his desk, tell whether any printer worldwide is out of paper - but he cannot tell if the production machine in the next room is even running (much less determine production data). A large amount of time, energy, and money has been spent on implementing and improving the information infrastmcture within manufacturing organizations. The emergence of Enterprise Resource Planning (ERP) and Manufacturing Execution Systems (MES) as indispensable components has provided important cost savings and productivity improvements. Using PCs for machine control provides plants with an opportunity that is very difficult to realize using traditional PLC technology. The PC is already a natural part of the information systems. When PCs are also the direct control platforms, they provide very detailed information about the plant floor itself. This information is very valuable to the rest of the production systems. The direct linking of the machines building products with the systems planning resource usage provides management with levers they would not otherwise have. These levers can be used to directly improve production efficiency and productivity-and therefore the bottom line.
暂无评论