PLC brand comparison
The programmable logic controller (PLC) market is dominated by a group of manufacturers that offer platforms with different strengths, costs, and software ecosystems. Selecting a PLC brand directly impacts system scalability, spare parts availability, ease of integration with existing industrial networks, and total cost of ownership over the entire life cycle of the installation. Factors such as I/O architecture, supported programming languages, software licensing model, and local technical support presence must be weighed according to the specific requirements of each application.
Industrial PLC selection factors
Section titled “Industrial PLC selection factors”The operating temperature range for typical industrial PLCs spans from -20 °C / -4 °F to 60 °C / 140 °F, although extended versions reach -40 °C / -40 °F and 70 °C / 158 °F. The most common supply voltages are 24 VDC and 120/240 VAC. Major manufacturers such as Siemens, Allen‑Bradley (Rockwell Automation), Schneider Electric, Omron, and Delta compete in advanced features such as coordinated motion control, real-time industrial Ethernet communications, and high-speed I/O processing capability. The following table summarizes the priority technical criteria when evaluating PLC platforms.
| Technical criterion | Typical range or specification |
|---|---|
| Operating temperature | -20 °C to 60 °C / -4 °F to 140 °F (standard); -40 °C to 70 °C / -40 °F to 158 °F (extended) |
| Supply voltage | 24 VDC / 120‑240 VAC |
| I/O capacity | From 10 points in micro-PLCs to more than 7000 points in rack systems |
| Programming languages | Ladder, structured text, function block, and SFC per IEC 61131-3 |
| Communications | Ethernet/IP, PROFINET, Modbus TCP/RTU, MQTT, OPC UA |
| User memory | From 8 kB in basic controllers to 50 MB in advanced platforms |
| Execution time per instruction | 0.02 µs to 0.5 µs in high-end CPUs |
Comparison of main manufacturers
Section titled “Comparison of main manufacturers”Leading brands include Siemens, Allen‑Bradley (Rockwell Automation), Schneider Electric, Omron, and Delta. Additionally, manufacturers such as AutomationDirect offer economical alternatives with competitive features. Siemens and Allen‑Bradley are estimated to hold a combined market share of over 50% in the high-end industrial automation segment.
| Manufacturer | Typical range | Max I/O | Highlighted communications | Estimated entry cost (USD) |
|---|---|---|---|---|
| Siemens (SIMATIC S7) | S7-1200 to S7-1500 | Up to 32000 | PROFINET, OPC UA, Modbus TCP | $300‑5000+ |
| Allen‑Bradley (Rockwell) | Micro800 to ControlLogix | Up to 10000+ | Ethernet/IP, CIP Motion, OPC UA | $400‑6000+ |
| Schneider Electric (Modicon) | M221 to M580 | Up to 16000 | Modbus TCP, Ethernet/IP, PROFINET | $200‑4000+ |
| Omron | CP1 to NX/NJ | Up to 8000 | EtherCAT, EtherNet/IP, OPC UA | $250‑3500+ |
| Delta | DVP to AS | Up to 4096 | Ethernet, CANopen, Modbus | $100‑2000+ |
| AutomationDirect | CLICK to Productivity | Up to 7000+ | Ethernet, MQTT, OPC UA | $104‑2000+ |
Implementation cost comparison
Section titled “Implementation cost comparison”PLC hardware cost represents only a fraction of the total implementation cost; programming software, I/O modules, configuration engineering, and long-term maintenance have a significant influence. For example, AutomationDirect’s programming software is free for all its families, while environments such as Rockwell’s Studio 5000 or Siemens’ TIA Portal require paid licenses with costs that can exceed $2000 USD per engineering seat per year.
| Item | AutomationDirect (Productivity) | Siemens (TIA Portal) | Allen‑Bradley (Studio 5000) |
|---|---|---|---|
| Programming software | No cost | License from ~$1000 USD | License from ~$1500 USD |
| Mid-range CPU | $123‑500 USD | $600‑2000 USD | $800‑3000 USD |
| Digital I/O module 16 pts | $60‑120 USD | $150‑300 USD | $100‑250 USD |
| Telephone technical support | Included | Per-incident or contract | Annual contract from $500 USD |
| Typical startup total cost (HW+SW) | $500‑1500 USD | $3000‑8000 USD | $4000‑10000 USD |
Software ecosystem and support
Section titled “Software ecosystem and support”Each manufacturer offers an integrated development environment that defines the programming experience and diagnostic capabilities. According to specialized sources, Siemens (TIA Portal) and Allen‑Bradley (Studio 5000) concentrate the largest number of online training courses, followed by Omron and Schneider Electric. AutomationDirect provides free software —CLICK Programming Software, Do-more Designer, and Productivity Suite— which lowers the entry barrier for small integrators. The support community and training offerings are summarized in the following table.
| Software platform | Manufacturer | License cost | Online training available |
|---|---|---|---|
| TIA Portal | Siemens | Paid (from ~$1000 USD) | Extensive; paid and free courses |
| Studio 5000 / RSLogix | Allen‑Bradley | Paid (from ~$1500 USD) | Extensive; multiple courses on Udemy |
| EcoStruxure Control Expert | Schneider Electric | Paid (from ~$800 USD) | Moderate; manufacturer’s own resources |
| Sysmac Studio | Omron | Paid (from ~$500 USD) | Moderate; official tutorials |
| ISPSoft / DIAScreen | Delta | No cost or low cost | Limited; technical documentation |
| Productivity Suite / Do-more Designer / CLICK | AutomationDirect | No cost | Growing; technical videos and forums |
Frequently Asked Questions (FAQ)
Section titled “Frequently Asked Questions (FAQ)”Which PLC brand is the most used in industry?
Section titled “Which PLC brand is the most used in industry?”Siemens and Allen‑Bradley (Rockwell Automation) are the most used in high-end industrial automation, with an estimated combined market share of over 50%.
Is it possible to program PLCs of different brands with the same software?
Section titled “Is it possible to program PLCs of different brands with the same software?”No. Each manufacturer uses its own development environment: TIA Portal for Siemens, Studio 5000 for Allen‑Bradley, EcoStruxure for Schneider, and Productivity Suite for AutomationDirect, among others. There is no single software that programs all brands.
Are there free programming software options for PLCs?
Section titled “Are there free programming software options for PLCs?”Yes. AutomationDirect offers free software for all its PLC families. Rockwell provides limited free versions such as RSLogix Micro Starter Lite, and Siemens offers trial versions of TIA Portal.
What is the main difference between a compact PLC and a modular PLC?
Section titled “What is the main difference between a compact PLC and a modular PLC?”A compact PLC integrates the CPU, power supply, and I/O in a single block (e.g., Siemens S7-1200, CLICK). A modular or rack-based PLC allows I/O modules, communication modules, and special function modules to be attached independently, facilitating expansion and maintenance.
Which industrial communication protocols should I consider when choosing a brand?
Section titled “Which industrial communication protocols should I consider when choosing a brand?”It depends on the existing ecosystem: PROFINET is predominant in Siemens environments, EtherNet/IP in installations with Allen‑Bradley, and EtherCAT is strong in motion applications with Omron. Modbus TCP/RTU is an open standard supported by almost all brands.
Is it necessary to buy a physical PLC to learn to program it?
Section titled “Is it necessary to buy a physical PLC to learn to program it?”It is not essential. Most programming environments include simulators that allow running and debugging the program on a computer without real hardware. It is estimated that professionals spend 80% of development time using only the simulator.
References
Section titled “References”- plcacademy.com: https://www.plcacademy.com/best-online-plc-training-courses/
- automationdirect.com: https://www.automationdirect.com/programmable-logic-controllers