Emergency stop button
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The \"Code for Design of Safety Instrumented Systems in Petrochemical Industries\" (GB 50770-2013) stipulates that emergency stop buttons, switches, signal alarms, etc., which are connected to the safety instrumented system, should use hardwired connections rather than communication methods. However, current chemical plants are operated from centralized control rooms, with the on-site control rooms located several kilometers away from the centralized control room; hardwiring is clearly not feasible in such cases. It can be achieved by using a communication relay cabinet; which standard does this come from?
Regarding the connection method between the emergency stop button and the signal alarm you mentioned, according to the \"Design Code for Safety Instrumented Systems in Petrochemical Industries\" (GB 50770-2013), it is indeed recommended to use hard wiring in order to reduce the risk of system failures. However, due to issues such as excessive distance in actual engineering projects, hard wiring is not always feasible; therefore, modern communication technologies are sometimes required to address such problems. The approach you mentioned of using communication relay cabinets to establish connections for safety instrumented systems does not specify exactly which standard it is derived from, as the GB 50770-2013 standard primarily sets requirements regarding direct hard wiring. However, with the advancement of technology and the demands of practical applications, the standards that can be referred to may be relevant industrial automation standards, industrial communication network standards, or the engineering practice standards of specific manufacturers. As norms and standards evolve over time, new regulations may emerge to allow the use of communication technologies in emergency stop systems. In actual project implementation, it may also be necessary to take into account the following standards or regulations: – Relevant industrial communication network standards issued by the International Electrotechnical Commission (IEC) ； - **or regional safety production regulations, industry standards ； - Internal safety management procedures and practices in factories ； - Technical specifications of communication equipment manufacturers. When implementing such a communication relay solution, it is necessary to ensure the reliability and security of the system, and to verify through certification and testing that the system meets relevant security requirements. If the specifications do not provide clear guidelines, it is possible to consult the local work safety regulatory authorities or hire a professional third-party agency for evaluation and guidance, to ensure that the system design meets actual safety requirements. In the absence of specific regulations, the design plan should fully consider potential risks and take appropriate safety measures. .
I didn’t understand what was being asked It is not specified that the emergency stop button is a local button
The emergency stop buttons are connected to the SIS control system via hard wiring. These buttons are divided into those located on-site and those in the CCR; the on-site buttons are directly connected to the DI cards of the SIS system at the FAR, while the emergency stop buttons on the auxiliary control panel in the CCR are connected via hard wiring to the DI cards of the SIS system in the remote cabinet there, which is connected to the SIS controller at the FAR.