[en] Nowadays, there are plenty of various Instrumentation and Control (I&C) systems under operation all over the world. They mostly cover all the industry branches, including safety-critical ones: heavy industry, oil and gas industry, nuclear and fossil power generation, etc. Although all I&Cs perform the most critical functions in the required way, they can be based on completely different technologies and principles. In many countries I&C systems for Nuclear Power Plants (NPPs) were designed by foreign companies and they typically integrate sets of specific hardware and software components, which continuously interact with each other. Such systems’ core is connected to NPP’s sensors and field devices. Thousands of process parameters are driven and controlled by I&C systems within the design-based limits of operational devices in a well-coordinated, efficient and reliable way. To accomplish this mission, NPP I&C systems measure the process parameters, calculate their deviation from the predefined design conditions, and generate corrective actuation commands to appropriate field devices providing continuous display of important safety-critical information, related to actual NPP parameters and deviations from set points, through the human-machine interface in appropriate control facilities. This is how operators are informed about real status of the NPP to effectively manage power production through the necessary actions and adjustments.