The CPU is the control system's brain, which uses its nerves comprising communication busbars and protocols to connect with its muscles and senses (IO modules) as well as with the closest and distant environments, i.e., other control systems, cloud services, or other systems. Last but not least, it also has its symbolic face taking the form of its display. SIMATIC control systems are a market leader in industrial automation, and the SIMATIC S7-1500 family is a SIEMENS flagship. We at Siemens Advanta CZ are responsible for the development of a wide range of features of these top-class product and development tools. Our responsibilities include the areas based on OS Linux, a part of communication systems, file systems, the embedded web server, and display. We test all features using our automated tests within a test automation framework, in whose development we are also engaged.