Introduction
OpenSource operating systems and applications for them are becoming more common. The emergence of high-performance and low-cost controllers with the Linux operating system allows use them as an alternative to traditional PLC in automation of production processes, and a wide choice of free software for the development of graphics applications allows you to create effective HMI. Project LxDCS - attempt to create a set of libraries and basic applications for create distributed control systems of technology processes.
Purpose
The package is intended for the development systems of automation of production processes different levels of complexity, from stand-alone data acquisition systems and PC-based control and microcontrollers to multi-level distributed systems including Linux-controllers, HMI-station and data server, connected to the LAN, with exchange of data in to realtime, distributed data processing and redundancy. Supports industry standard protocols allows use the systems as PLC and other devices. The package is designed for professionals who have an know UNIX/Linux systems and programming in C language, although, as the 10-year-old practice of using, to create simple systems Collecting enough data set included in the application package.
Ideology
When designing the system architecture used in the following principles:
- Compact code with minimal use of external libraries and toolkits.
- Portability to different hardware platforms, and other UNIX-like OS without changing the source code.
- Using the same applications on all levels - from the microcontroller to the server.Any application can work both independently and in any combination of elements of the system.
- Scalability - the possibility of constructing a simple autonomous control systems to geographically distributed systems.
- Maximum simplification of the design of control programs, new applications and io drivers using the library of software patterns and LxDCS.
LxDCS software does not use of standard commercial SCADA systems technology, the effectiveness of which raises many questions:
- Any graphical configuration tools. applications are configured editing plain text files, as is common on UNIX systems. Thus, to change the parameters of any system component you must have only remote access (telnet, ssh, FTP). The process of reconfiguration does not require stopping or restarting LxDCS hosts.
- OPC technology, which most cases, complicates and slows down the process of data exchange. For communication with devices of I / o in the base system uses standard interface protocols adopted in industrial automation, allows the use of a large number of standard equipment. The simple architecture of the system enables even a novice programmer to create drivers for any custom devices that have an open Protocol.
- SQL-DBMS. As practice shows, this technology is extremely inefficient for working with similar technological data, especially in real-time. In LxDCS for storage use its own database. For export it is possible to create arrays of data in the form .csv files. If necessary, it is possible to develop an SQL interface to the database or any other method of obtaining data, as the database has a simple and open structure.
- IEC-languages. For writing sophisticated control programs used by the C language and library package. Also, there are no limitations to create applications in any other language, allowing for direct work with memory and files. Compared with the IEC-languages that greatly enhances the management of complex processes that require large amounts of computation or complex algorithms. In prosthesic cases, sufficient basic data processing (arithmetic, extracting square root, logical operations) these operations can be performed directly in I/O drivers using directives in a configuration file.
Set of packet
- Input-output subsystem.
- Data archiving subsystem.
- Network subsystem.
- X Window GUI subsystem.
- WEB GUI subsystem.
- Library of functions for developing control applications, IO drivers and GUI.
Contact
For questions and offers, as well as if you would like to join the development - Email: lxdcs@yandex.ru
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