I have few questions on SIL Calculation. I have a PILZ controller in SIF and try to make some calculation by hand. Controller has DI and DO with CPU.
If I would like to calculate PFDavg for Controller then I should combine DI, DO and CPU PFD avarage, correct? (No redundancy at DIs and DOs) For ex, PFD input, single + PFD output, single+ PFD CPU = 2,20 x 10^-4 + 1,30 x 10^-5 + 6,20 x 10^-5 (See please certificate)
As you see the certificate shows only PFD but not λ DU. Can I calculate my λDU from PFD as referencing the formula below? PFDavg = (λDU * T)/2 . Actually, the certificate does not say what T has been taken into account on PFD calculation as well, but I am going to take it as 1 year.