The Difference Between PLC and RTU

What is an RTU?

A PLC, or programmable logic controller, is a form of RTU, or remote terminal unit. It is a little device that controls and observes a process from a distance.

RTUs are frequently employed in industrial environments where it would be unsafe or too harsh for people to be present. They are also employed when a large-scale process needs to be monitored or managed.

RTUs can be used to monitor and manage anything, including pressure, temperature, and motor speed. They can also be used to turn equipment on or off based on certain criteria.

Remote Terminal Units are referred to as “RTUs.” Also, they are known as “Remote Telemetry Units.” An RTU is a piece of electronic equipment that a microprocessor manages. An RTU’s primary job is to connect the SCADA to any physical objects that are present. Supervision Control and Data Acquisition is referred to as “SCADA.” The supervisory system messages used to control all connected objects and the transmission of all telemetry data to the system serve as the interface between the objects and SCADA.

Control loops and control algorithms are not supported by the RTU. Since cheaper technology has caused the capabilities of RTUs and PLCs to begin to converge, the industry has standardized the language for RTU programmers.

Also, they can frequently operate on solar power or batteries due to their isolated locations, where even the power source is distinct. They even use less energy than a PLC does. RTUs have a wider geographic telemetry than PLCs.

What is an PLC?

A ruggedized computer called a Programmable Logic Controller, or PLC, is used for industrial automation. Digital computers are PLCs. They are mostly utilized to automate electromechanical processes, such as factory assembly lines, light fixtures, amusement park rides, etc.

They are specifically made for various inputs and output configurations and can withstand a range of temperatures, are resistant to vibration and impact, etc.

Process control, relay control, motion control, networking, etc. are a few of the features of PLC. They have begun to match desktop computers in terms of data handling, processing, communication, and storage.


Both PLCs and RTUs are electrical devices, and their functionalities are similar. Both PLCs and RTCs are sold with features that are similar to each other. Since the industry made the functional language used by RTUs and PLCs to run these programs a standard, many companies market proprietary alternatives and many related environments.

Communication Speed and Data Transfer

A PLC transfers data at a quicker rate than an RTU. Moreover, a PLC will be used to convey all process and programming data.

RTU, however, will only send required data and modifications to it. In essence, a PLC drives its programs in a cyclic fashion, whereas an RTU drives its programs in an event-driven manner (trigger-based).


Compared to a PLC, an RTU is far more resilient to assaults and extreme weather conditions.

RTU is especially made for remote IO applications where wireless data transfer is required and the IOs are dispersed widely around the facility. As a result, it is more efficient and difficult to use than a PLC.

Also, they may frequently operate on solar power or batteries due to their isolated locations, where even the power source is unique. They even use less energy than a PLC does. RTUs have a wider geographic telemetry than PLCs.

IO Control

Unlike valves, pumps, motors, etc., RTU is often not utilised for output control.

The primary causes are intermittently bad wifi networks and low power usage. The operation of outputs may be hampered. PLC is the greatest choice in the situation.

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Which Situations Are More Appropriate for PLCs or RTUs?

It’s time to choose which solution best suits your needs now that you are aware of the distinctions between a PLC and an RTU. These are some situations when PLCs or RTUs would be more appropriate.

A PLC is often a better option for bigger projects, such as managing electrical power distribution or a factory assembly line. These kinds of extensive controls are perfect for the PLC’s potent processing capabilities. On the other hand, an RTU is frequently the preferable choice when you need to remotely manage and monitor equipment in more remote places, such wind turbines or solar power plants.

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