Understanding driving overtaking

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For those working in coal chemical industry for the production of synthetic ammonia, there is a \"start-up override\" controller between the molecular sieve unit and the cold box in the purification section. After searching on Haichuan, several explanations were found: Override control and selective control mean the same thing. Usually, when a fault occurs during operation, there are two types of protection mechanisms in place. One is called hard protection, which means that in the event of a fault, no other emergency measures are available, so the process must be stopped to address the issue. The other type is soft protection, also known as override control; when a fault occurs, another control mechanism is activated automatically, thereby ensuring continuity of production and enhancing safety levels. In override control, there is usually an override controller that operates in either low-or-high selection mode, choosing one from multiple input signals; its main function is to provide a safety interlock mechanism. Override control refers to the mechanism by which, when an automatic control system receives abnormal signals such as accident alarms, deviations beyond acceptable limits, or failures, the override logic immediately carries out functions such as automatically switching to manual mode, giving priority to increase or decrease operations, prohibiting increases or decreases, etc. This allows the system to be brought into a pre-set safe state, while simultaneously generating alarm signals. The vast majority of control systems previously built using conventional control instruments lacked the capability to identify the quality of the status of devices both within and outside the system. As long as there is a deviation signal at the input, the controller will take corresponding action, regardless of whether there are problems within the system or if the external production equipment is not functioning properly. Sometimes, the control mechanism may deviate from the set values, leading to accidents. Override control can effectively suppress the aforementioned adverse effects. Internally, it acts as the eye that monitors the automatic control process, constantly checking the quality of transmitter signals in the control loop, as well as the input and output deviation limits. If there is a problem with the control instrument itself, the control loop loses the basic conditions necessary for automatic control; in such cases, the override control mechanism will switch the control loop to manual mode automatically. Externally, it acts as a safety switch for the system. When everything related to the automatic control instruments is functioning properly, but there are changes in the operating status of the main and auxiliary equipment or various automatic control systems, the override control will determine the control strategy or operating direction of the automatic control system based on the results of its evaluation logic, thereby switching to a safe mode and avoiding potential dangerous situations. “\"Override\" control is another name for selective control. An override control system is primarily designed with production safety in mind, and it is characterized by two or more controllers sharing one actuator. One of the controllers operates during normal production, while the other acts as a override controller and remains in standby mode. When abnormal conditions arise, it takes over from the regular controller to ensure a seamless transition, and it continues to operate until the conditions return to normal, after which control is transferred back to the original controller. I wonder if this place also means the same as what was said above?