When it comes to documenting your safety function, there are two parts to this; First Hardware verification where you prove that your solution meets the required Performance Level (PL) or Safety Integrity Level (SIL) and second the software piece of your safety function. The various parts of the safety function can be scattered all over the PLC code implemented in various function blocks, routines, etc. For anybody other than the programmer it is very time consuming to understand where these parts have been implemented. It is therefore pivotal to show this in a document. At ADVANTIS this is part of the Design Verification Report where a block diagram shows all the different parts of the safety function.
Each of these blocks shown above is then further described explaining the purpose, the functional description and most important the cross-reference into the PLC code.
With this kind of information, an inspection body for example has a much better chance of understanding the programmer’s intention and will bless a ride in a shorter time.
Best regards,
ADVANTIS Team
