The ControlLogix System

Learn Logix Part 2.1. This article gives an overview of the ControlLogix system and introduces the components that make up the ControlLogix system such as the ControlLogix chassis, power supply, and controllers.

Learn Logix is a series of articles designed to teach you everything you need to know to work with Rockwell Automation’s Studio 5000 Logix Designer and the Logix 5000 series of PLCs.

In the last part of the series, we learned about the various systems that make up the Logix 5000 platform. You can find that part here or if you’re new to the series, you can find all of the previous parts here.

The Logix 5000 ControlLogix system is made up of ControlLogix controllers, ControlLogix chassis, ControlLogix power supplies, and, optionally, I/O and communication modules.

Since the ControlLogix system is a multi-controller system, it is possible to place more than one controller in the chassis. Controllers, I/O modules, and communication modules can be placed in any order and location within the chassis.

Let’s look at these components in more detail.

ControlLogix Power Supply

The ControlLogix Power Supply

The ControlLogix power supply is located outside of the chassis. It provides electrical power that energizes all of the modules mounted in the chassis.

The ControlLogix power supply is available with 120V AC, 230V AC, and 24V DC input.

It’s worth noting that the ControlLogix power supply does not provide power to field devices mounted outside of the chassis. These devices need a separate power supply.

ControlLogix Chassis

The ControlLogix Chassis

The ControlLogix chassis is a physical housing for ControlLogix modules. Inside the chassis, there is a backplane that creates an electrical connection between the modules mounted in the chassis.

In the example above, you see a chassis with ten slots, however, ControlLogix chassis are available in various sizes to suit the requirements of different projects. The ControlLogix chassis is available in 4, 7, 10, 13, and 17 slot configurations.

Each slot in a chassis has a number. Slot numbering always goes from left to right starting at 0. So, a ten slot chassis has slots 0–9.

ControlLogix Controllers

ControlLogix Controllers

ControlLogix controllers are available with different combinations of memory and processor speed to suit the requirements of different applications and are capable of addressing large numbers of I/O points and networked devices.

The latest series of ControlLogix controllers are the L7 and L8 series of controllers.

ControlLogix Systems

A Complex ControlLogix System

ControlLogix systems can range in size and complexity. A simple ControlLogix system may consist of a standalone controller and I/O modules in a single chassis. A more complex system, like the one shown above, may have multiple controllers, multiple chassis, and network connections to other devices.

It’s worth noting that a chassis doesn’t require a controller. It only requires a communication module to communicate on the network. In the example above, the chassis at the top of the picture has a controller and the other chassis do not — they are used as remote I/O stations in the system.

Conclusion

In this article, we learned more about the components that make up the ControlLogix system. Specifically, we learned about the ControlLogix chassis, power supply, and controllers.

In the next part of the series, we will look in more detail at the ControlLogix controllers available and the differences between them. If you haven't already, be sure to sign up to the mailing list below to be notified when that part is available.

Update: You can find the next part of the Learn Logix series, The ControlLogix Controllers, here. This article gives an overview of the features of the L7x and L8x ControlLogix series of controllers. It also explains the differences between the L7x and L8x ControlLogix controllers.

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