Functional Safety 2014

Revealing Failures By Diagnostics

‣

A test is called a Diagnostic Test when that test

‣

Is carried out automatically, AND

‣

Is carried out frequently, AND

‣

Is used to reveal failures that could jeopardise the safety function, AND

‣

Results in an automated safe response

‣

Usually a diagnostic test is a “built-in” feature

‣

For example a memory test, CPU test, watchdog, …

‣

Example analogue input module

‣

Normally designed according to 61508-2 and 61508-3