Hello again,

In my last post, I introduced you to the concept of industrial automation. In that post, I provided a definition of industrial automation and showed how a manual process could be automated.

In this post, I want to introduce you to automation systems. Automation systems are the underlying technology that controls automated processes.

One of the easiest ways to understand automation systems is to look at the basic system architecture that defines all automation systems. That's exactly what we'll do in the next section.

Before we move on, I would like to take a moment to introduce myself to anyone who might be new here.

My name is Ken Bourke and I have worked as an automation professional for almost a decade. During this time, I have worked on large global projects in different industries around the world.

In the last year, I have started producing content online to share my knowledge through free blog posts and free or (very) reasonably priced courses.

If you get some value out of this post then consider checking out my courses, joining the mailing list using the form at the bottom of this page, or, if you’re feeling very generous, buying me a coffee using the Buy Me a Coffee widget on this page.

With that bit of shameless self-promotion out of the way, let’s get back to the content.

Automation System Architecture

All automation systems, regardless of their size or complexity, have similar components and architectures. The basic architecture of an automation system is made up of;

Inputs

Inputs send information from the physical world to the automation system.

Inputs allow an automation system to understand the state of a process or to receive commands from a system operator.

Logic Devices

Input devices send data to logic devices.

Logic devices are the brains of the automation system. A logic device analyses its inputs and makes decisions based on rules that have been pre-defined and downloaded to the logic device.

In a commercial product like a microwave or a dishwasher, the logic device is usually a microprocessor.

In industrial automation systems, the logic device is usually a PLC, short for Programmable Logic Controller. A PLC is a special type of computer designed to act as a logic device for industrial automation applications.

Outputs

After making a decision, a logic device actuates output devices to control a process.

Output devices allow an automation system to influence the physical world.

Automation System Example

Now that we understand the architecture of an automation system, let’s see how these components can be linked up to create an automation system to control an automated process.

The automation system that controls an automated conveying process may be made up of these components connected together with simple electrical wires;

• sensors to detect when products are present on the conveyor,
• a PLC-based logic device, and
• motors to transport the products that are detected on the conveyor.

When an operator places a container on the conveyor, the sensor detects the container and its status changes. The PLC detects the new status of the sensor and, based on its program, actuates the output for the motor. The motor receives the output from the PLC and runs, transporting the container along the conevyor.

Wrap Up

In this post, we got an introduction to automation systems by looking at the basic architecture that all automation systems follow and by looking at an example of how the components of an automation system can work together to control an automated process.

In my next post, I will dive into more detail about each component that makes up an automation system and use the body analogy to make the concept of an automation system easier to understand.

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