What are the different types and components of PLC?

PLCs stand for Programmable logic controllers and are digital computers for automating electromechanical processes such as lighting fixtures, control of machinery at the factory assembly lines or amusement rides. They are used in many machines and automotive and other industries.
They are majorly designed for multiple outputs and input arrangements, elevated temperature range, noise immunity and vibration, and impact immunity. They are lightweight, rugged devices functioning without air conditioning, fans or electrical filtering.


Different Components of Programmable Logic Controller

There are three major PLC components, these are:
1. Processor
2. Power Supply
3. Input/output (I/O) section

1- The Processor

The processor acts as the intellect of the PLC system. It’s a solid-state device designed to perform many functions in machine tool, process control function and machine tool. Formerly, relays, convectional electromechanically devices and associated wiring executed these functions.
These same functions are provided by the PLC offering control function varieties on a broader scope with minimal effort making it a preferred choice.
Processors operate on DC power supplied by the power supply. Internal DC power is routed through processors operating in I/O portion and the PLC service port connected devices.
It can only be changed with the user having the programmable devices. This program is unaltered with power offs and failure conditions.

2- Power Supply

The power supply provides DC power for the PLC system. It offers internal DC to operate the processor logic circuitry with the input/output assemblies.
The majorly use power levels are 120 VAC or 24 DC


3- Input/Output Section

The internal circuitry of the PLC operates at low levels of voltages making them vulnerable to electrical spikes from the power lines, noise or load kick-backs. Due to this vulnerability, the Input/output portion of the PLC plays a critical role in averting them.
Some of the input devices are potentiometers, push buttons and pressure switches. The input module converts high voltages from input devices to logical low-level voltages that can be used for internal processing by the CPU. An input module can process both analog and digital input
Some of the output devices are the solenoid, contractor coils, and lamps. In the output section, the CPU low-level generated logic signals pass these modified signals to the final control elements in operating the output devices.
The PLC is connected to many types of inputs and outputs. They are categorized into two groups that are analog and digital. Digital inputs and outputs operate because of a discrete or binary change like yes/no or on/off.
Analog inputs and outputs continuously change in a variable range like the potentiometer, pressure, and temperature.


Different Types of Programmable Logic Controller

There are three main types of PLC:

1- Unitary PLC control panel,
2- Modular PLC control Panel and,
3- Rack-mounted PLC control Panel

1- Unitary PLC Control Panel

Unitary PLC control panel is a primary controller consisting of the power supply, the central processing unit (CPU), input and output module. In this simple mechanism, Unitary PLC is directly attached to process machinery use.
These control panels are used for a simple process like the automatic access gates.


2- Modular PLC Control Panel

It’s a more complex module having multiple modules grouped to create a customized controller system. This system has a main module having a power supply, CPU and input module. Additionally, this system has multiple output modules that can be added as with the process requirement.
The best thing about the control panel is that whenever one module fails, only that module is replaced. Compared to Unitary PLCs,  Modular PLCs are more expensive. However, it offers a better choice with simultaneous production processes.

3- Rack-Mounted PLC control Panel

Rack Mounted PLC control is where additional output modules are mounted on organized racks and within a network connected to a panel. It has multiple modules making it quite similar to a modular PLC panel. Larger systems can be built with this approach without complications and cluttering. It has well-organized modules on a rack that can be reinserted and removed as required.
Rack mounted PLCs are highly considered in lengthy industrial processes due to the automation it provides and the variety it offers. It’s a typical set up in factory settings.
The cost of PLC India varies as it depends on the type that you want. You can always search online from Alibaba and choose one from there. In the description, you’ll get to see the PLC model, country and place of origin, condition, warranty and payment details.

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