Is there any supported way to integrate a data-diode into this? This would allow far more secure remote monitoring of systems by exfiltrating real time data through the data-diode, and having certainty that you don't risk of control infiltration.
I would not move it between Node-RED and the PLC but I see other applications of a data diode. We usually create a very small DMZ around each machine and a data diode can additionally protect it (see also a very old article from us: https://docs.umh.app/docs/getting-started/usage-in-productio... ) You could place the data diode as a "firewall" between the internet and the edge PC.