How can I determine the cause of the Lectus OPC Server freezing?

Question

Modbus

Good afternoon,
there is a Lectus OPC Server that takes several variables via Modbus and broadcasts them via OPC.
The OPC client (vibration monitoring system) is running on the same server.
And so, periodically, broadcast on OPC is randomly hung up.
This whole structure can work for a week, two, or maybe a couple of hours.
Errors are visible in the Lectus logs, something like adress violation, but at this moment the broadcast is no longer happening, respectively.
How can I check if the problem is hardware or software?
Those. there are two assumptions that the modbus controller or the communication line fails, or this is a purely software glitch, here I have no understanding of how to check and exclude either one or the second.