In the process of designing systems that support production tasks, many operational nuances are taken into account. Each complex is individual, but the principles of its implementation are based on a basic set of requirements. The system must be efficient, reliable, functional and at the same time ergonomic. The link between the directly technical part of production support and management tasks is implemented by controllers for process automation. They concentrate information coming from different technological areas, which is the basis for making certain decisions.
Classification of controllers by application
Practically every modern enterprise uses systems to some extent to automate work processes. Moreover, the nature of the serviced functions can be completely different. Thus, in the field of the chemical industry, programmable equipment controls dosing, supply volumes of bulk and liquid materials through controllers, monitors the properties of various substances using sensors, etc. In the service sector of transport organizations, the emphasisis done on the control of power equipment, as a rule, loading and unloading. Universal controllers for automation of ventilation, heating and water supply systems are also widespread. This is a group of systems that manage utilities at enterprises in various fields. Conversely, there are highly specialized areas in which it is necessary to develop individual systems for specific needs. These areas include the oil industry and metallurgical plants.
How controllers work
Industrial controller is a microprocessor, which provides hardware and software. The first part, in fact, serves the physical operation of the system, based on the nested task execution program. An important aspect of any configuration of this type is the regulatory infrastructure. That is, the software base is responsible for making certain decisions, but in the future, the received signals are sent to the points of commands given directly to the working equipment. Thus, automation controllers control machines, conveyor lines, technical power facilities, etc.
Another no less important component of the overall control infrastructure are sensors and indicators, based on the indicators of which the controller develops decisions or strategic chains that determine the operating modes of the equipment. These can be sensors that evaluate the condition of devices and units servicedmaterials, microclimate parameters in the production room and other characteristics.
Architectures of automation controllers
Under the architecture of the controller is understood a set of components, due to which the function of controlling automation is implemented. As a rule, the architectural configuration assumes the presence of a processor, network interfaces, storage device and I / O systems in the complex. This is a basic package, but depending on the needs of a particular project, the composition and characteristics of individual parts may vary. Complex controllers for automation are called modular. If the traditional simple architecture is a unified block with a typical composition of functional elements that are not available for change by the operator, then in complex architectural models a multicomponent modular configuration is implemented. It allows not only maintenance of a single closed unit, but also each module separately. Now it is worth considering the individual parts of the architecture in more detail.
Varieties of architecture modules
The basic modular device is represented by a microprocessor. It depends on its power how complex the tasks solved by a particular controller can be. The storage device also matters. It can be integrated into the system without the possibility of further modification. But most often external flash memory modules are used, which can be changed independing on current tasks. I/O devices are largely responsible for the actions that industrial automation controllers take. Through these channels, the processor receives information for processing and further issues the appropriate commands. In modern complexes, interface modules play an increasingly important role, on which the communication capabilities of the controller depend.
Main characteristics of the processor module
When developing a control system, it is especially important to take into account the basic characteristics and capabilities of the microprocessor. As for the main operating parameters of this module, they include clock frequency, bit depth, task execution periods, memory, etc. But even these characteristics do not always become decisive, since the performance of modern even budget microprocessors is enough to service most of the production processes. It is much more important to determine the communication capabilities and functions that controllers perform to automate the work of the enterprise. In particular, according to the requirements, operators put the ability to work with a wide range of network channels, interfaces and programming languages in the first place. Separately, it is worth noting the ability to connect display devices, controls, modern displays and other components.
Operator panel
Regardless of the characteristics of the filling of the controller, to control its functions, an operator station with an appropriate relay must be provided. Outwardly, such devices resemble a smalla computer provided with input and output devices, process sensors and a display. The simplest controllers for industrial automation provide for the possibility of programming through this panel. Moreover, programming can mean elementary settings for entry-level commands. The most sophisticated operator terminals also perform self-diagnosis and self-calibration.
Automation power supplies
The average range of voltages supplying industrial controllers is in the range of 12-48 V. The source is usually a local 220V network. At the same time, the power supply is not always in close proximity to the equipment being serviced. For example, if controllers are used to automate a boiler house in a metallurgical multi-stage production, then a distributed power network can be equidistant from several energy consumers. That is, one circuit will serve the boiler for soft metals, and the other for hard ones. At the same time, the voltage in the lines can also change.
Conclusion
Workflow automation systems are increasingly becoming part of the infrastructure of modern enterprises. Accordingly, controllers for automation systems in various modifications are also widely used. In itself, the maintenance of such a device does not require special costs. The main difficulties in working with this equipment relate to the quality of programmingand optimization of the configuration layout. But at the same time, to simplify operator functions, modules that assume self-configuration according to the main data entered by the user are becoming more and more popular.
