Can DI (NON-SIL) trigger DO (SIL)?
Answers
If I get you correctly, you have a signal (input) from process (which is in Non-SIL application) and with the use of that signal you want to control the ESD or PSD system (in SIL application).
The manual is correct, that a NonSIL DI can't be used in SIL application, means you can't use Non SIL IO modules in the hazardous enviroment.
Please remember, both these PCS and ESD mostly are not in the same unit (or zone), I mean not part of same control system. So you need some sort of MMS or IAC communication to pass the information from PCS to ESD. There you have to be careful when you pass some SIL restricted information to the SIL application. If you can filter out such information, then pretty good and safe. Otherwise, you may get unnecessary safety shutdown because of CRC conflict with SM and PM.
Hope, this helps.
Hi,
You have not indicated the SIL of the application say SIL2 or SIL3.
Yes. As per AC 800M Hi Safety Manual it is not recommended to use Non-SIL signals in SIL application. When it is said Non-SIL signal DI signal it must be coming from Non-SIL Iinput module other than DI880. Non-SIL certfied IO modules can be used in SIL2 application but in SIL3 application we cannot use since it will prevent download to PM865 controller.
Refer AC 800M HI Safety Manual, 3BNP004865-516 Page-73.
Similarly, It is not allowed to use output parameters from Function blocks or OCntrol Modules marked with NONSIL in the parameter description in a way that can influence the safety function of SIL classified application. If such code affects an output from SIL3 appliaction, it might result in a Safety Shutdown. Refer Page-103 of AC 800M HI Safety Manual.
Hope this information will help you.
Regards,
Kumaraswamy. B
It is not allowed to use output parameters from Function Blocks or Control
Modules marked with NONSIL in the parameter description in a way that
can influence the safety function of a SIL classified application. If such
code affects an output from a SIL3 application, it might result in a Safety
Shutdown. on page 103
BNP004865-516
Source: Refer AC 800M HI Safety Manual, 3BNP004865-516
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