A PLC (Programmable Logic Controller) is a single digital computerized system that controls industrial processes such as production, assembling, and other robotic devices, unlike a DCS panel that has multiple microprocessors. This differentiates a PLC from a DCS panel. Apart from being widely used in industries for manufacturing processes, PLC is also used for processes that require high reliability on control, easy programming and diagnosis of process faults. It is like a real-time system with quick output response for an input. A PLC was initially used by the automobile industry, but it was eventually adopted by other industries. To accommodate different industrial programs and processes, different types of PLCs were introduced. Some common types of PLC are as follows.
Unitary PLC Control Panel
A Unitary PLC is a basic type of controller that consists of the power supply, the input module, the central processing unit(CPU) and the output module. For this simple mechanism, a unitary PLC is directly attached to the process machinery. Apart from being the most basic type, it is also the cheapest and most easy to port system. Due to the simplicity of the system, unitary PLC control panels are used for simple single processes such as automatic access gates.
Modular PLC Control Panel
A modular PLC control panel is a more complex control panel that consists of multiple modules, grouped together to create a customized controller system. The system has a main module with the basic system consisting of the power supply, CPU, and an input module. Apart from these, the system has multiple modules of output that can be added or removed as per the process requirements. The best part about this control panel is that in case one of the modules fails, only that module needs to be replaced. When compared to a unitary PLC control panel, modular PLC control panels are expensive. This control panel is a good choice for production process with many simultaneous processes.
Rack-mounted PLC Control Panel
The design of a rack-mounted PLC control panel is quite similar to that of a modular PLC control panel as it also contains multiple modules. In a rack-mounted PLC control panel, the additional output modules are separately mounted on a rack and connected to the panel through a network. This type of design enables firms to have large control panels without them being overly cluttered. Since the control panel is huge, the cost is high too. Also, with a larger unit, this system has more input and output points than any other PLC unit.
When it comes to extensive industrial processes, PLCs are a highly considered type of control panel. The reason for this consideration is the amount of industrial automation it provides and the various types that are available. For more information on the different types of PLCs and to choose one for your process, get in touch with a control panel provider and installation expert.