Hey everyone! 
I wanted to share some insights and solutions I’ve discovered while working with Node-RED, especially when dealing with external devices that might disconnect or lose communication. I’ve been using Node-RED on my TrueNAS setup, and it’s been a fantastic tool for automating various processes around my home. However, I ran into a specific issue that I thought might be helpful to discuss here.
The Problem: I have an external TCP Modbus device that occasionally stops communicating. When this happens, my Node-RED flows would hang or stop functioning properly. I tried several approaches to handle errors and restart the flows automatically, but nothing seemed to work initially. After some research and experimentation, I finally found a solution that works for me!
The Solution: I realized that monitoring the connection status was key. By focusing on the Connected and Disconnected status messages, I could trigger a flow restart whenever the device went offline. I used a Switch node to monitor these statuses and implemented a simple flow to restart the affected processes. Here’s a quick breakdown of how it works:
- Monitor Connection Status: Use a Modbus or Serial node to continuously check the device’s connection status.
- Trigger on Disconnection: When the device disconnects, the Switch node detects the Disconnected status and triggers a restart sequence.
- Restart Flows: I found a handy solution from the Node-RED forum that allows restarting flows programmatically. This was the missing piece that made everything work seamlessly!
Additional Tips:
- Scheduled Resets: As an added precaution, I set up a daily timer to reset the flows at 5 AM. This ensures that everything starts fresh every morning, even if there were any unnoticed issues overnight.
- User Interface Feedback: I integrated a button in my Homey interface to display the last restart time, giving me peace of mind that the system is self-maintaining.
Why This Matters: For anyone working with external devices, especially those prone to connectivity issues, having an automated recovery system is invaluable. It saves time troubleshooting and ensures that your smart home setup remains reliable and responsive.
Looking for More Insights? If you’ve encountered similar challenges or have tips to share, I’d love to hear from you! Whether it’s about Node-RED, Modbus, or any other automation tools, let’s keep the discussion going. Happy automating! 