Thanks both of for your replies. I will admit that I am in a situation where I am stabbing in the dark. And maybe this problem has nothing to do with Node-RED, so for that, one of the moderators can remove this post if they wish. And I really don't like long forum posts, but here goes...
OK, backing up a few days....The flow that I have in place uses the value from the Rice Lake unit by receiving it using the serial node, configured as shown below. It works great usually for hours at a time, then suddenly data stops arriving, but Node-RED is still running (and Node-RED shows no error messages that I can find). If one looks at the weight on the Rice Lake unit, it's correct and will change if material is added or removed from the scale. The problem happens downstream from there, i.e. the Pi stops receiving the data. Everything works again once I restart Node-RED.
My original plan of attack was to view the Node-RED logs, but all I continue to get is the [info] logs (not [debug], despite changing the settings.js file).
My next idea was to see if the Pi was overheating or something else, so I installed Telegraf to send the data to Influx. But that did not go smoothly (this is my first Telegraf installation) and I am still trying to work it out via the InfluxDB forum..
I next thought that the serial port (or perhaps the serial cable) randomly stopping was causing this. Some posts I found on this topic:
- Serialport.on('data') stops reading data / stops working after some time · Issue #2117 · serialport/node-serialport · GitHub
- python - Serial stops reading after about 6 hours - Stack Overflow
- c - Ubuntu Serial Communication: reads failing and then coming in all at once - Stack Overflow
In addition to swapping out the cables, I could also swap the Pi with an identical one. And then I thought that maybe changing the comm protocol (RS485, i.e. two way communication, instead of RS232, which per the above is doing only one way communication) might help, but now I am less inclined to think that will help.
The next time it starts and I am near the equipment, I will power cycle the Rice Lake unit to see if that does anything to help Node-RED resume, but like I said above, the Rice Lake unit always keeps displaying the correct weight throughout the whole debacle, so I do not believe that is the source of the problem.
