Raspberry Pi in Industrial Applications

Raspberry Pi boards are not PLC replacements, but they’re excellent companions. I use them to extend visibility, prototype fast, and integrate modern services without disturbing validated control systems. Here’s how.

1. Common Use Cases

• Data Gateways: Collect PLC, Modbus, or sensor data and publish to MQTT/OPC UA.
• Edge Analytics: Run Python or Node-RED scripts for OEE, quality checks, or AI inference.
• Protocol Bridging: Translate between legacy serial devices and modern cloud APIs.
• Maintenance Tools: Host diagnostic dashboards, documentation, or VPN endpoints.

2. Hardware Considerations

• Use industrial-grade Pi models (Compute Module, Pi 4/5) with rugged enclosures.
• Add UPS HATs or DC-DC converters to handle 24 VDC inputs and ride through power dips.
• Integrate digital isolation when interfacing with high-voltage signals.

3. Software Stack

• Deploy 64-bit Raspberry Pi OS Lite for minimal footprint.
• Containerize applications with Docker; define Compose stacks for reproducibility.
• Use Ansible or GitOps pipelines to manage fleet configurations.

4. Reliability Practices

• Store code and data on SSD/NVMe rather than SD cards to reduce wear.
• Monitor temperature and throttle conditions; add heatsinks and fans if necessary.
• Enable watchdog timers to auto-reboot on lockups.
• Implement store-and-forward queues for network outages.

5. Security

• Harden SSH access, disable default accounts, and enforce key-based logins.
• Segment networks; use VLANs and firewalls to prevent lateral movement.
• Apply automatic security updates during maintenance windows.
• Encrypt sensitive data and rotate certificates regularly.

6. Integration with PLCs

• Communicate via OPC UA, Modbus, Ethernet/IP drivers, or vendor APIs.
• Respect PLC scan times; avoid excessive polling and implement caching.
• Document write permissions and apply role-based access to prevent unauthorized control.

7. Compliance and Validation

• Validate Pi-based solutions just like any automation component: run FAT/SAT, document tests, and include them in change management.
• Use CE/UL-rated enclosures when required by plant standards.

8. Case Example

At a beverage plant, we deployed Pi gateways beside CompactLogix PLCs to stream production metrics into Power BI. By offloading reporting to the Pi, we avoided costly PLC upgrades and achieved a payback in under two months.

When engineered responsibly, Raspberry Pi platforms unlock modern connectivity and analytics while letting PLCs focus on real-time control.