Low Power Consumption, High Performance
ARM-based processors (e.g., Cortex-A series) deliver strong computational capabilities with low power consumption, ideal for industrial scenarios requiring continuous operation.
Rich Interface Support
Supports industrial communication interfaces such as GPIO, CAN, RS-485, Ethernet, and USB, enabling direct connectivity to sensors, actuators, and industrial bus devices.
Compact and Rugged Design
Industrial-grade construction (wide temperature tolerance, vibration resistance, dustproof) ensures reliability in harsh environments, with a small form factor for embedded deployment.
Linux/RTOS Compatibility
Runs Linux (e.g., Debian, Ubuntu Core) or real-time operating systems (e.g., FreeRTOS) to meet real-time requirements.
Open Source and Cross-Platform
Complies with IEC 61131-3 standards, supporting programming languages like Ladder Logic and Structured Text (ST), and runs on Windows/Linux/Raspberry Pi platforms.
Flexible Deployment
Compatible with x86/ARM hardware, deployable as a soft PLC (on general-purpose computers) or hard PLC (e.g., Raspberry Pi, ARM industrial PCs).
Protocol Compatibility
Built-in support for Modbus TCP/RTU, MQTT, OPC UA, and other protocols, facilitating integration with SCADA, HMI, and cloud systems.
Extensibility
Allows custom function blocks via Python/C++ to integrate AI algorithms or third-party libraries.
Example: Food Packaging Machinery Control
ARM industrial PC (e.g., NXP i.MX8) runs OpenPLC to control servo motors and pneumatic cylinders via Modbus RTU.
HMI touchscreens interact with OpenPLC via Modbus TCP for real-time monitoring.
Advantages: Costs 1/3 of traditional PLC solutions, with support for custom algorithms (e.g., visual quality inspection).
Example: Photovoltaic Power Station Monitoring
ARM gateway (e.g., Allwinner T507) runs OpenPLC to collect inverter data (RS-485) and upload it to the cloud via MQTT.
Local logic control (e.g., battery charge/discharge strategies) is executed directly by OpenPLC.
Advantages: Edge computing reduces cloud workload and supports offline operation.
Example: AGV Scheduling Control
Multiple ARM industrial PCs (e.g., Rockchip RK3568) run OpenPLC to coordinate AGV paths via CAN bus.
Integrates ROS nodes for SLAM navigation, with OpenPLC handling motor control and obstacle avoidance.
Advantages: Unified hardware-software design simplifies multi-device coordination.
| Aspect | ARM + OpenPLC | Traditional PLC (e.g., Siemens S7-1200) |
|---|---|---|
| Cost | Hardware cost reduced by over 50% | High hardware/licensing fees |
| Customization | Deep customization (drivers/algorithms) | Closed ecosystem, vendor-dependent |
| Ecosystem | Seamless Python/Node.js integration | Limited to TIA Portal/CODESYS |
| Use Cases | SMEs, R&D, rapid prototyping | Large-scale, high-reliability systems |
Real-Time Limitations: ARM + Linux lacks native real-time performance; use kernel patches or FPGA coprocessors.
Long-Term Maintenance: Open-source version updates may cause compatibility issues; lock versions and maintain forks.
Security Risks: Harden Linux systems (e.g., disable default SSH ports, enable SELinux).
The combination of ARM industrial computers and OpenPLC offers a cost-effective, lightweight PLC solution for industrial automation, particularly suited to scenarios requiring rapid iteration and customization (e.g., smart agriculture, lab equipment). For mission-critical environments (e.g., nuclear plants, railways), traditional PLC reliability must still be evaluated. As the ARM ecosystem matures (e.g., RISC-V industrial chips), this approach is poised to expand further into industrial markets.
