Regarding the use of dual or triple architecture in SIS systems
Thread Content
I have a question for the experts: The SIS system uses dual controllers. Does the SIS system become non-functional when one of the controllers fails, or only when both controllers fail? When the SIS system uses triple controllers, does it cease to function when two of those controllers fail, or only when all three controllers fail?
In a dualized SIS system, the system is typically designed such that if one controller fails, the other can take over all functions; therefore, the SIS system will only fail when both controllers fail. In a triple-redundant SIS system, the 2oo3 configuration (two outputs and three votes) is typically used, meaning that the system can function properly as long as any two of the controllers are operating normally. Therefore, the system can fail as long as two controllers malfunction. If two more controllers remain functional, the system continues to operate. When all three controllers fail, the system will definitely fail. .
If the two meters operate on a 2-out-of-1 logic, and one of them fails, interlock is triggered； If it follows a 2-out-of-2 logic, if one table fails, as long as the other table still shows normal operation, there will be no interlock ； Generally, three tables use a 3-out-of-2 logic: if one table fails while two are functioning properly, there is no interlock ； Two instruments failed, triggering interlock ；