What is an Emergency Stop System (ESD)?

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What is the definition of an emergency stop system? 　 The Emergency Shut Down System (ESD), also known as the Safety Interlocking System (SIS), is a control system that automatically responds to and intervenes in dangerous situations that may arise in petrochemical and other manufacturing facilities, or in situations where failure to take action would lead to further deterioration. It serves to ensure production safety and prevent serious injuries to people and significant property losses. In terms of structure, emergency shutdown systems can be divided into dual-redundancy and triple-redundancy types. The dual-redundancy ESD system features a dual configuration from the I/O modules to the CPU and communication modules. One of the sets is in operation, while the other is in hot standby mode. The main difference between a triple-redundancy ESD system and a dual-redundancy ESD system is that in a triple-redundancy ESD system, all three units are operational at the same time; therefore, it requires more advanced hardware diagnostic functions. When a hardware failure is detected in one of the channels, the system immediately issues an alarm and adjusts the selection mechanism for that channel accordingly, yet the system can still operate safely. Hence, triple-redundancy systems are also referred to as \"redundant fault-tolerant\" systems. What are the characteristics of an emergency stop system? (1) The ultimate goal of the system is to ensure the safety of the manufacturing process and to protect production equipment and operators from harm ； (2) The switch input detection element is selected to be closed in the normal state; a broken circuit equates to an interlock action, meaning the system is fail-safe ； (3) The output solenoid valve or relay is set to normal excitation, and it will operate only in the event of a fault in the output circuit ； (4) When the production plant is shut down for any reason, the state of the target components controlled by the ESD system must be such as to ensure production safety.