CompactLogix and ControlLogix run the same Logix control engine and are programmed in the same Studio 5000 software. They differ in scale, hardware architecture and availability features. This page explains what each platform is, compares them side by side, and shows how to choose.
Independent resource. Not affiliated with or endorsed by Rockwell Automation. Figures checked against Rockwell publications on September 28, 2026.
CompactLogix is the machine-level Logix platform. A single controller sits on a DIN rail or panel with its I/O modules attached beside it. It is sized for a standalone machine, an OEM skid or a packaging cell. ControlLogix is the chassis-based Logix platform. Controllers, I/O and communication modules plug into a 1756 chassis, several controllers can share one chassis, and the platform supports controller redundancy. It is the usual choice for large, multi-machine, process and high-availability systems.
For a programmer, the two feel almost identical. Both are programmed in Studio 5000 Logix Designer, both use tag-based addressing with user-defined data types, both organize code into tasks, programs and routines, and both share the core Logix instruction set. A seal-in rung, a TON timer or a UDT-based motor routine is written the same way on either. What changes is the I/O configuration, the capacity limits and the system architecture.
If you arrived here searching for “CompactLogix” and want the bigger picture of Allen-Bradley controllers, including MicroLogix, SLC 500 and Micro800, start with the Allen-Bradley PLC guide.
CompactLogix is Rockwell Automation’s family of Allen-Bradley Logix 5000 controllers for machine-level and mid-range control. On Rockwell’s product pages at the time of writing, the family is made up of:
5069-L320ERP) integrates with the PlantPAx 5.0 system.In US plants, CompactLogix shows up on packaging lines, conveyors and material handling, OEM machines and skid-mounted process equipment. It is also the target Rockwell names for moving off SLC 500. Existing 5370 and older 1769-based systems remain common in the field, so expect both 1769 and 5069 I/O when you do maintenance work.
ControlLogix is the chassis-based Logix platform. A ControlLogix system is a controller, 1756 I/O modules and network communication modules in a 1756 chassis with its own power supply. Rockwell’s selection guide notes that any module can go in any slot. Larger systems can put multiple controllers in one chassis and join controllers across networks. Controllers in the same chassis operate independently and communicate over the backplane.
1756-L81E and 40 MB for the 1756-L85E), a 1 Gb EtherNet/IP port and a USB port. Controllers support 100 to 300 EtherNet/IP nodes depending on the model. The controller supports up to 32 tasks, and code can be written in ladder, structured text, function block and SFC.Redundancy is the feature that most often decides the platform. ControlLogix redundancy uses 1756 redundancy modules in a redundant chassis pair. If the primary controller faults, a secondary takes over. Rockwell’s selection guide notes the trade-offs. Redundancy is designed for non-safety, high-availability applications. Redundant controllers communicate only with standard I/O. Controllers enabled for redundancy do not support motion, and on the 5580 the embedded Ethernet port is disabled when redundancy is enabled.
Maintenance is the other practical difference. 1756 ControlLogix I/O modules support removal and insertion under power (RIUP). Your plant’s lockout/tagout and electrical safety procedures still apply. Catalog numbers with a K or XT suffix add protection for harsh, corrosive environments, and some XT versions are rated for extended temperatures.
Capacity figures are the ranges Rockwell publishes for the current mainstream controllers: CompactLogix 5380 and ControlLogix 5580. Your exact limits depend on the catalog number, firmware and Studio 5000 version.
| Aspect | CompactLogix | ControlLogix |
|---|---|---|
| Programming software | Studio 5000 Logix Designer | Studio 5000 Logix Designer |
| Languages | The Logix 5000 languages: ladder, structured text, function block diagram and sequential function chart | The Logix 5000 languages: ladder, structured text, function block diagram and sequential function chart |
| Hardware form | Controller with I/O modules attached beside it on a DIN rail or panel (no separate chassis) | Modular 1756 chassis with a separate power supply; any module in any slot |
| Local I/O platform | 5069 Compact 5000 I/O on the 5380 and 5480. Older 5370 controllers use 1769 Compact I/O or 1734 POINT I/O | 1756 ControlLogix I/O, which supports removal and insertion under power (RIUP) |
| User memory (current generation) | CompactLogix 5380: 0.6 to 10 MB depending on catalog number | ControlLogix 5580: 3 to 40 MB depending on catalog number |
| EtherNet/IP nodes | CompactLogix 5380: up to 180, depending on catalog number | ControlLogix 5580: 100 to 300 depending on catalog number, with more available through 1756 communication modules |
| Embedded Ethernet | CompactLogix 5380: 1 Gb EtherNet/IP with dual configurable ports that support dual-IP mode | ControlLogix 5580: one 1 Gb EtherNet/IP port; add 1756 communication modules for more networks |
| Multiple controllers per rack | No; one controller per system | Yes; multiple controllers in one chassis operate independently and talk over the backplane |
| Controller redundancy | Not offered on CompactLogix | Yes, with 1756 redundancy modules in a redundant chassis pair (non-safety, high-availability applications) |
| Safety version | Compact GuardLogix 5380: up to SIL 2/PLd (1oo1) or SIL 3/PLe (1oo2) | GuardLogix 5580. Every ControlLogix 5590 includes integrated functional safety |
| Typical application | Standalone machines, OEM equipment, packaging, material handling, smaller process skids | Plant-wide and multi-machine systems, process and batch, high-availability and large motion systems |
Sources: Rockwell Automation CompactLogix 5380 product page, ControlLogix selection guide 1756-SG002D and user manual 1756-UM543, accessed September 28, 2026. We do not list prices. Hardware and software pricing varies by distributor, region and agreement.
Work through these questions in order. The first one that clearly points to ControlLogix usually settles it.
If the process must keep running through a controller fault, as in continuous process, utilities and some critical infrastructure, you are looking at ControlLogix redundancy. Remember its limits: non-safety applications, standard I/O only and no motion on redundancy-enabled controllers.
Count the EtherNet/IP devices you will add to the I/O configuration: drives, remote I/O adapters, HMIs, vision systems and robots. Compare that count with the node limit of the controller you are considering, leaving room for growth. Do the same for memory once you have an estimate of the program size. A line-level system that could reach hundreds of networked devices generally points to ControlLogix.
A 1756 chassis can hold multiple independent controllers plus communication modules for several networks, all sharing the backplane. CompactLogix is one controller per system.
Both platforms offer integrated motion on EtherNet/IP and a safety version (Compact GuardLogix or GuardLogix), and every ControlLogix 5590 includes integrated safety. Check the axis count and safety rating your risk assessment requires against the exact catalog number. Do not rely on a family-level summary.
Spare parts on the shelf, technician familiarity and the plant’s engineering standards often matter more than a spec sheet. A machine builder shipping to a ControlLogix plant may still choose CompactLogix for a standalone machine, and that is fine. The programming skills are shared.
Choose a current family for new work. Check each catalog number in Rockwell’s Product Lifecycle Status tool. “Active Mature” means fully supported, but a newer product exists. “End of Life” means a discontinuation date has been announced.
The same: the Studio 5000 editor, tag database, data types (BOOL, DINT, REAL, TIMER, COUNTER, UDTs), the task, program and routine structure, add-on instructions, and the core instructions such as XIC, XIO, OTE, OTL/OTU, TON, RTO, CTU, MOV and the compare instructions. Our Studio 5000 tutorial and RSLogix 5000 tutorial apply to both platforms.
Different: the I/O configuration tree and the module-defined I/O tags it creates. Those tags follow a Location:Slot:Type.Member pattern, such as Local:1:I.Data, and their members depend on the module family, so 1756 and 5069 modules do not look identical. Chassis and slot layout, network module setup, redundancy configuration and capacity limits also differ. When you move logic from one platform to the other, the routines and UDTs usually come across cleanly. The I/O mapping is where the work is.
Versions matter on both. To go online with or download to a Logix controller, you need the Studio 5000 Logix Designer major version that matches the controller’s firmware major revision. That is why US plants commonly keep several versions installed side by side, and why a download guide such as our Studio 5000 download guide starts with “which version do you need?”
Coming from RSLogix 500? SLC 500 and MicroLogix programs are file-based. Moving them to CompactLogix or ControlLogix means translating N7, B3 and T4 addresses into tags. RSLogix 500 includes a Logix Designer Export feature that converts SLC 500 projects into a Studio 5000 project. Rockwell’s manual is clear that it converts ladder only, not SFC or structured text, and that the converted file still needs I/O mapping and review. For MicroLogix specifics, see the MicroLogix 1400 guide.
You do not need a CompactLogix on your desk to practice the logic that runs on one. The Allen-Bradley PLC simulator on this site has an Allen-Bradley-style learning dialect covering XIC, XIO, OTE, OTL, OTU, TON, TOF, CTU and CTD with named tags. You write rungs, run them against a simulated machine and get pass/fail feedback on behavior. Scenarios such as motor start/stop, forward/reverse motor and conveyor sort mirror common machine-level CompactLogix jobs.
Be clear about the boundary. The simulator is independent and is not Rockwell software. It does not open .ACD files, emulate CompactLogix or ControlLogix firmware, configure I/O modules or go online with a controller. It does not support RTO, ONS, OSR or RES. For testing a real Logix project without hardware, Rockwell’s product is Studio 5000 Logix Emulate. Our Logix Emulate alternative page explains when each makes sense.
A free account includes 27 practice records and the first 6 core lessons in each dialect, including Allen-Bradley.
Figures and lifecycle statements on this page come from Rockwell Automation’s public pages and publications, accessed on September 28, 2026. Specifications vary by catalog number and change over time, so confirm them for your application.
Seal-in rungs, timers, counters and interlocks work the same way on CompactLogix and ControlLogix. Practice them in a browser, then carry them to the real platform.
Allen-Bradley, Rockwell Automation, CompactLogix, ControlLogix, GuardLogix, Compact GuardLogix, Studio 5000, Logix Designer, Logix Emulate, PlantPAx and RSLogix are trademarks of Rockwell Automation, Inc. PLC Simulator is independent and is not affiliated with, endorsed by or sponsored by Rockwell Automation.