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© ABB
| Slide 20
2
nd
Generation Safety Systems
…better but not perfect
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2
nd
generation systems..
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Were developed and certified in accordance to
standards (i.e. IEC 61508)
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Provide additional software diagnostics to help identify
latent faults
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However, they still …
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Rely on redundancy for safety as well as availability
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Focus on identical paths and voting for Safety
(hardware fault tolerance)
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Do not use diversity to eliminate common cause issues
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Certification is conducted by an accredited third party entity
Nov 04, 2014