【Weekend Share-17】What requirements must SIS hardware meet?

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This post was last edited by zhoudingshengs on 2024-12-20 11:15. 1. What requirements must the hardware for SIS meet? 【Answer】 1. Check for safety certifications (technical standards); generally, for SIS systems, the German Rhein TUV safety certification is required. Other reputable certifications include the French BV, TUV Nord in Germany, and E*da in the United States. Generally, capable SIS systems will obtain these certifications. Currently, fake certifications are everywhere; since there are no regulations at the international level or in our country specifying which entities have the authority to issue certifications, fake certificates abound. However, generally, reputable SIS manufacturers will give priority to obtaining certification from German Rhein TV. 2. The hardware must be redundant (per engineering standards); any SIS must have a redundant hardware architecture. Typically, three CPUs operate simultaneously. The CPU, power supply, input/output cards, and communication modules of the SIS system should be configured in a redundant manner. Clause 8.4.5 of GB50770 requires that the central processing unit, input unit, output unit, power supply unit, communication unit, etc., of the logical controller shall be independent units, and it shall be possible to replace these units online without affecting the normal operation of the logical controller. 3. Independence of the SIS system: Independence is an engineering standard for SIS systems; any SIS used for interlock functions must not be used for process control. 4. Fault safety: Fault safety is a fundamental requirement for SIS systems. In addition to the hardware and software configurations of the SIS system itself, routine inspections involve checking the relays; when normal interlocks are not activated, the relays should remain powered, with the connections set to the normally open (NO) state. In the event of a SIS failure or a problem with the power supply, the relays lose power, the contacts disconnect, and on-site solenoids are activated, among other things. 5. Bypassing interlocks requires authorization and proper procedures. 6. The SIL assessment of the safety instrumented system is the most direct criterion for determining whether the safety instrumented system is qualified; generally, by looking at the SIL classification and the verification report, it is possible to determine whether such SIS system is qualified.