cossoft:
It's just that I'm not experienced with the reliability of long term Arduino USB linkage...
You are facing the commonplace problem that more potential points of failure are created by adding systems to monitor the reliability of a process.
You need answers to these questions
- Without any monitoring in place what are the consequences of the main process failing and what is the probability of that?
- With monitoring in place by how much will the duration of a typical main system failure be reduced?
- With monitoring in place what are the consequences (and probabilities) of either {A} an undetected main system failure and {B} a false report of a main system failure.
Efforts to reduce the probability of main system failure - for example an automatic switch to a parallel system - may be a better use of your resources if a failure has significant consequences. This is why I suggested earlier that you research how other high reliability severs are managed.
...R