ICS cyber security has focused on the Ethernet portion of ICS networks. The only way to address the intersecting issues of reliability, safety, security, and resilience is to understand the validity of the sensor input by cross correlating sensor inputs in real time before they become Ethernet packets. Sensor electrical characteristics monitoring provides multiple benefits, including identifying sensor drift or sensors out-of-calibration, providing a basis for extending calibration/testing intervals, providing a basis for continued operation when network monitoring identifies cyber vulnerabilities, and providing resilience when sensors are inoperable for any reason. Process sensor cyber concerns are not idle considerations as there have been multiple catastrophic failures from process sensor-related incidents, including at least one case where a sensor was hacked, preventing a critical system from starting. This presentation will provide case histories and discuss the issues with deploying this 2nd security monitoring network at Level 0 / Level 1.