Suspected serial port problem -- how to view logs?

I have two flows, where each one runs independently of the other. Each flow has a serial input node that receives the value from a Rice Lake weigh indicator via RS232. I am using this RS232-to-USB cable to convert from the signal wires to USB. The program runs fine so long as the weights keep flowing. However, each flow will unexplicably stop after any number of minutes or hours (sometimes it runs 30 minutes, sometimes 15+ hours), and I suspect the serial cables, the Rice Lake units, or even something in the Pi.

image

The two extra boards you see connected to the Pi above are these. I have them sending 0 to 10 volt signals out based on the weight received from the serial input.

I originally thought I could get at the problem by checking the logs (which is admittedly something I have never done when using Node-RED). I changed my settings.js file as shown to have the level debug:

but when I run node-red-log, I still get just the info type logs:

21 Sep 13:29:59 - [info] [function:scale weight in] switch= true
21 Sep 13:29:59 - [info] [function:scale weight in] switch= true
21 Sep 13:29:59 - [info] [function:scale weight in] switch= true
21 Sep 13:30:00 - [info] [function:scale weight in] switch= true
21 Sep 13:30:00 - [info] [function:scale weight in] switch= true
21 Sep 13:30:00 - [info] [function:scale weight in] switch= true

Can anyone suggest a way to try to log / view what might be happening at the serial port level, just to see if that is indeed the source of the problem?

What does "stop" mean?
Data stops arriving but node-red is still running? Node-red crashes / exits? Something else?

Data stops arriving, but node-red is still running (and node-red shows no error messages that I can find).

I have placed a debug node after each serial node and when the next stop happens, I will see what is displayed.
image

1 Like