APCS is a system consisting of personnel and equipment combined with the software used for the automation of functions of personnel management of industrial facilities: power plants, boilers, pumps, water treatment plants, food, chemical and metallurgical plants, oil and gas facilities.
APCS are classified as follows:
Automation type is selected for the object, and may be a hybrid of several systems.
Modern software and hardware complex of an automation systems is divided into three levels: upper (computers), medium (controllers), the bottom (field equipment, sensors, actuators).
Upper level — a server and user PC (or workstation). It shows the state of the process, and hence gave the command to change the process parameters at the operator need. To develop control algorithms it is possible to use different SCADA systems (depending on the task), which implicitly can be divided into server and client. The server part is made of sensors survey, collection, archiving and data processing, and the clients poll the server and display it on the operator monitor. Engineering stations are used to make changes to the work of workstations, servers and controllers, as well as display the diagnostic information of the control system components.
The term «server room» and «client room» are conventional. In fact, the division is made under license in the components used by the SCADA system, and each manufacturer has its own licensing policies. Until the separation on: the number of processed signals, protocol drivers, the number of work stations, the ability to create web-based interface, the mobile interface, and so on. Therefore, the selection of a license, requires full source project data, and is to be confirmed on the terms of reference developed by the system.
In its turn, the operation of the system involves two modes: the design and operation mode (runtime). These modes are determined by the type of license for the full functioning in operation, it is enough to get functioning mode (runtime). If it is planned to modify the algorithms of the system, for example, in order to expand, a license is needed for development mode. Both modes are independent, and can be run on different workstation, for example editing of algorithms is possible without stopping the process at an engineering workstation, followed by updating software on the primary workstation.
One of the essential features is the «backup», it is very important to be able to restore the reports on the operation of the system in the event of something unexpected or for the global analysis in slow and long process.
SCADA system constantly puts all the data collected in the database. They can be viewed as graphs (trends) and, if necessary, if stipulated in the terms of reference, implemented in the form of discharge reports to Excel or other formats.
The systems developed by us writing speed and storage capacity depend on the complexity of the system. For rapidly parameters changing the speed can reach 200 000 times per second and above, thus, the amount of disk space for storage and archiving of such a large number of parameters can be up to several tens of terabytes.
The system is able to inform the operator about the current and alarm events. They also certainly are to be archived. In general, the messages are divided into current and important (emergency). Current are hidden in the archive and alarm log is always displayed on the operator screen. Sometimes text alert messages can be accompanied by sounds.
Medium level — PLC, programmable logic controllers. Here everything is quite simple; often physically PLC consists of separate modules. For programming each PLC has its own development environment, some manufacturers of hardware and software integrate it with SCADA.
The following modules can be a part of the PLC:
Bottom level – is the eyes, nose and ears of the system, namely, all the sensors and actuators that perform various conversion values into standard signals that are clear for the average level of the system, as well as various valves, motorized actuators, and other control mechanisms.
Consider our sample script development of reliable distributed automatic control system based on modern software and hardware of companies such as National Instruments, Siemens, MDS, or other. Selection of equipment and software is executed on the basis of technical requirements, financial possibilities and wishes of the customer.
The system may have different requirements, such as obligatory self-diagnosis systems, the possibility of further development (modernization) of the system by simple additions of necessary modules, supply measurement and control channels, and others.
For example, the average complexity of ACS is based on a set of measuring instruments, processing and management of a single network, and includes the following components:
This system can be both local and connect to the server data processing and storage using industrial Ethernet network via various network equipment, followed by the organization of specialized places of operators and engineers for human intervention in individual transactions, in order to maintain control over the process, so and due to the complexity or otherwise of the automation of certain operations.
In such ACS components connections is performed by using analog and digital signals, and communication components of middle and upper levels — by using the industrial Ethernet network (eg, the PROFINET protocol).
The main equipment of the medium level (PLCs, inverters, power supplies, operator panel) is set to specialized electrical cabinets with varying degrees of protection from the environment, and may include the climate system for the installed equipment.
These technologies allow the use of automation panels made in areas with high dust content, as well as in unheated pits at any time of the year.
ur solutions make it possible to reconstruct or develop, produce and introduce APCS of any complexity «turnkey» with the following properties:
All the engineering stage are performed with the latest technologies and in accordance with the GOST.
As a result of engineering works, we get a turnkey modern and certified system of automated process control of an enterprise with full documentation in Russian (schematic diagrams, wiring diagrams, cable magazines, cabinet layout diagrams, block diagrams, mathematical and provision of information, user manuals and service personnel) and equipped with all the necessary software.