Top PLC Brands Engineers Trust for Industrial Automation

PLCs are an important part of modern industrial automation. There are a few more common and popular PLC brands that consistently hold the majority of the global market. Some of the best manufacturers in the industry include Siemens, Rockwell Automation (Allen-Bradley), Schneider Electric, Mitsubishi Electric, and Omron. The PLC software market is in very good health and offers many good options for your automation needs.

Understanding Programmable Logic Controllers

PLCs are rugged computers built for the factory floor, designed to operate machines and processes with extreme reliability. Each PLC runs a continuous loop called a scan cycle: it reads from inputs, executes a user program, and updates outputs. This process repeats thousands of times every second.

A complete PLC system consists of several core components:

• CPU: the processor that runs the application
• I/O Modules: connect the system to field devices such as sensors, motors, and valves
• Memory: stores the control program and runtime data
• Power Supply: provides stable DC voltage to the system
• Communication Links: allow the PLC to exchange data with external devices like HMIs, computers, and other controllers

Criteria for Selecting PLC Brands

Engineers consider many variables when selecting among a variety of PLC brands. For example, in selecting a PLC based on technical requirements, the most important considerations are:

• How fast the CPU runs
• The size of memory
• The number of I/O capabilities
• All communication types (protocols such as EtherNet/IP, Profinet).

In addition to these basic features, engineers must also assess software, environmental considerations (how robust it is), and how accessible technical support is to facilitate these evaluations.

Beyond technical specs, other factors play a role in PLC selection. These include industry-specific requirements, environmental conditions such as extreme temperatures, high humidity, or corrosive atmospheres, scalability for future growth, and compatibility with existing systems. Always consider the total cost of ownership, including hardware, software licenses, training, and long-term maintenance

Rockwell Automation (Allen-Bradley)

Rockwell Automation is a powerful company operating in North America. Many people recognize the Allen-Bradley name as a quality manufactured product line with exceptional reliability. The company’s stronghold in the North American market is unrivaled, enabling engineers throughout the USA and Canada to become familiar with the Allen-Bradley product line, thereby establishing a large customer base.

Rockwell offers scalable controller families:

• ControlLogix for large, high-performance systems
• CompactLogix for mid-range applications
• MicroLogix/Micro800 for small, standalone machines

Rockwell also provides customized solutions for automotive, food and beverage, pharmaceutical, and energy/logistics industries. If you would like to check out our blog going over suitable MicroLogix applications, you can find it here!

Siemens

Siemens is considered one of the largest automation companies in the world today. A 2025 report by Global Market Insights indicates that Siemens holds a large share of the global PLC market at 20.1%, making it an automation giant.

Siemens’ primary product line consists of its lineup of SIMATIC controllers. The SIMATIC S7-1200 is an efficient controller used for completing smaller to moderately sized tasks. In contrast, the high-performance SIMATIC S7-1500 is used for handling complex, high-speed operations with advanced motion control in larger applications.

Siemens PLCs are very good at handling complex or very large projects. Audi uses SIMATIC controllers to standardize and optimize processes for building car bodies, improving both efficiency and quality in manufacturing.

Mitsubishi Electric

Mitsubishi Electric has earned a reputation for speed, precision, and reliability. The company’s flagship product lines include the MELSEC iQ-R Series for medium to large systems and the MELSEC iQ-F Series for small-scale applications with built-in Ethernet. The iQ-R platform features CC-Link IE TSN networking with a minimum communication cycle of 31.25 µs, synchronization accuracy of ±1 µs, and support for up to 256 synchronized axes.

These PLCs are ideal for high-speed inspections using vision systems, packaging machinery requiring precise torque control, and complex assembly operations involving multi-axis synchronization.

Schneider Electric

Schneider Electric delivers a variety of automation products from control equipment for machines to solutions for managing energy consumption. The Modicon product line demonstrates the flexibility of these automation products through three product categories:

• M580 series for tough industrial automation that includes Ethernet networking and strong cybersecurity
• M340 line for many types of machine automation (packing, conveyors, etc.) that offers a wide range of communication options.
• The M580 and M262 product lines (flagship products) are engineered for use in IIoT (Industrial Internet of Things) environments. Both product lines are designed with integrated cybersecurity features, Ethernet infrastructure, and support for mobile devices, and are certified by TÜV for process and machine safety.

Schneider PLCs are ideally suited for infrastructure and utility-related projects. An example of this is the Modicon M340 series, which quickly adjusts the chemical levels and flow rates of treated water in water treatment plants by controlling pumps, valves, and filtration equipment.

Omron

The durable and dependable components manufactured by Omron are engineered to operate reliably under harsh working conditions, which is why engineers rely on Omron controllers for their precision and stability, resulting in very little downtime.

The Sysmac Automation platform consists of the NJ and NX series controllers. The NJ501-5300 (NJ-series NC Integrated Controller) provides high-accuracy motion control and all the advanced functions of numerical control in a single controller.

The Omron controllers are particularly well-suited to the industries listed below that use production systems. For example, an integrated food processing facility can utilize the conveyor belt, robotic arm, and machine vision to improve throughput and accuracy in product packaging, food and beverage Production, and digital device production.

Final Thoughts

Each of these manufacturers brings different strengths to the table. Rockwell Automation dominates North American installations with deep integration across its Allen-Bradley ecosystem. Siemens leads globally with a broad portfolio spanning small machines to enterprise-level process control. Mitsubishi Electric delivers high-speed precision for demanding motion applications. Schneider Electric bridges machine control and energy management on a single platform. Omron focuses on tightly integrated automation with built-in vision and robotics support. The right choice depends on your application requirements, your region, your existing infrastructure, and the level of vendor support available to your team.

Whether you are building a new project and looking for the right controller ecosystem or sourcing a replacement to get the line back moving, we at DO Supply carry a wide range of PLC hardware from brands covered in this article. We supply spares, accessories, parts, motion control, and more, all tested and backed by our two-year warranty. Visit our site today, or give us a call, and we can help take your automated solution to the next level.