What Is a ControlLogix 5580? An Introduction to the 1756 Controller Platform and System Components

In my last post, I showed you how to set a Logix 5000 PLC's IP address using the EtherNet/IP Address Commissioning Tool. Before you can do that for a ControlLogix system, it helps to understand exactly what you're working with. In this post, I'll give you a detailed introduction to the 1756 ControlLogix 5580 controller platform and walk you through the physical components that make up a complete system.

What Is the ControlLogix 5580?

The ControlLogix 5580 is Rockwell Automation's high-end Logix 5000 controller platform, designed for large, complex, or multi-discipline applications. Like CompactLogix, it's programmed with Studio 5000 Logix Designer and shares the same tag-based programming model.

The key difference from CompactLogix is that ControlLogix is chassis-based. Instead of snapping together directly, the controller and its associated modules all install into a 1756 chassis. The chassis provides backplane power and communication to every module installed in it.

The ControlLogix 5580 succeeds the 5570 generation and delivers significantly higher performance. Compared to a 5570, a 5580 controller offers 5x to 20x better overall performance, supports up to 256 servo axes per controller (up from 100), handles up to 320 unconnected buffers (up from 40), and can process up to 256 simultaneous messages (up from 16). It also adds a built-in 1 GB EtherNet/IP port that wasn't available on the 5570.

Reading a ControlLogix 5580 Catalog Number

All 1756 ControlLogix 5580 controllers follow a consistent catalog number format. Take the 1756-L85E as an example:

• 1756 identifies the ControlLogix product family
• L indicates it's a controller (Logix processor)
• 8 is the controller generation
• 5 indicates the memory tier
• E indicates a built-in EtherNet/IP port

The 5580 family spans five models: the 1756-L81E (3 MB, 100 EtherNet/IP nodes), 1756-L82E (5 MB, 175 nodes), 1756-L83E (10 MB, 250 nodes), 1756-L84E (20 MB, 250 nodes), and 1756-L85E (40 MB, 300 nodes).

GuardLogix 5580 controllers follow the same catalog number format with an S suffix to indicate the integrated safety partition.

Key Hardware Features

The ControlLogix 5580 includes several hardware features worth knowing:

• A built-in 1 GB EtherNet/IP port for network connectivity and project downloads
• A USB port for local connections when Ethernet isn't available
• A memory card slot for storing and loading projects without a laptop. The controller ships with a 2 GB SD card installed, and has been tested with cards up to 32 GB.
• A four-character status display for monitoring controller state at a glance
• A reset button for fault recovery
• Integrated energy storage, meaning no battery is required
• An onboard display that enhances diagnostics and troubleshooting
• An optional conformal coating for harsh environments

Unlike CompactLogix, the ControlLogix controller doesn't have a built-in power supply. Power to the chassis and modules comes from a separate 1756 power supply module that installs into the leftmost position of the chassis.

ControlLogix also supports a much wider range of specialty modules than CompactLogix, including redundancy modules, motion modules, and a broader selection of communication modules for networks like ControlNet, DeviceNet, and Data Highway Plus.

Studio 5000 Logix Designer version 28 or later is required for the 5580 controller, with version 29 adding support for the 1756-L81E, 1756-L82E, and 1756-L84E models.

ControlLogix 5580 System Components

A ControlLogix 5580 system is built from these key components: a 1756 chassis, a 1756 power supply, a 1756 controller, local 1756 I/O modules, and optional 1756 communication modules.

The 1756 Chassis

The chassis is the backbone of a ControlLogix system. It holds all the modules and provides backplane communication and power distribution between them. Chassis come in different sizes, from 4-slot up to 17-slot, depending on how many modules the application needs.

Modules are installed by aligning them with the slot guides and pressing firmly until the backplane connector seats. A module latch secures each module in place.

One note on chassis compatibility: while a 5580 controller will physically fit into an older 1756 Series B chassis, the maximum operating temperature is derated to 50°C in that configuration. For full-rated operation up to 60°C, you need to use it in a Series C or later chassis.

The 1756 Power Supply

The power supply installs into the leftmost position of the chassis and provides power to the backplane, which in turn powers every module in that chassis. It doesn't occupy a numbered slot; it has its own dedicated position.

Power supplies are available in different output ratings and input voltage options (120/240VAC or 24VDC input), so you can match the power supply to your panel's available power source. The ControlLogix 5580 controller itself draws approximately 6 watts.

The 1756 Controller

A ControlLogix controller can be installed in any numbered slot of the chassis and communicates with other modules over the backplane. A single chassis can contain multiple controllers, which communicate with each other over that same backplane. In simplex mode, there's no restriction on how many controllers can share one chassis, though you'll want to be cautious if you're running four or more with heavy backplane traffic.

1756 Local I/O Modules

ControlLogix uses I/O modules to add I/O points. The 1756 I/O platform offers a wider variety of options and higher-density configurations than CompactLogix, which is part of what makes it suitable for larger applications.

Local I/O modules communicate with the controller over the chassis backplane.

Communication Modules

One of the advantages of the chassis-based design is that you can add communication modules to support additional networks. Common options include EtherNet/IP communication modules (such as the 1756-EN4TR), ControlNet modules, and DeviceNet scanner modules.

Multiple communication modules can be installed in the same chassis, which is useful for systems that need to bridge between networks or support a large number of remote I/O devices. Adding EtherNet/IP communication modules is also how you expand beyond the node limit of the controller's built-in port.

Slot Fillers

Since the ControlLogix chassis is a fixed size, you may find yourself with empty slots. To protect the backplane from dust and debris, fill any unused slots with a 1756-N2 slot filler.

Wrap Up

You now know what the ControlLogix 5580 is, how to read its catalog number, what hardware features it includes, and what the key components of a complete system look like. This gives you the context you need before wiring one up or configuring it in Studio 5000 Logix Designer.

If you want to take the next step and learn how to program ControlLogix PLCs, sign up for a 30-day free trial of Controls Engineering Academy today to learn PLC programming using browser based simulations with no hardware or software required.