Functional Safety 2014

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| Slide 23

System 800xA High Integrity

Application Execution

Parallel diverse execution

allows a hardware fault

tolerance of 1 for SIL3

applications

HFT = 1 (SIL 3 Execution)

Safety Module

SM

I/O-Data

Superv. Logic

CEX Bus

ModuleBus

I/O-Data+CRC

1131

SIL3

I/O-Data

1131

SIL3

Superv. Logic

Processing Module

PM

Safety I/O

I/O-Data

Diverse Exec.

Diverse Exec.

I/O-Data+CRC

SFF

Hardware fault tolerance

0

1

2

< 60 %

Not allowed SIL 1

SIL 2

60 % - < 90 % SIL 1

SIL 2

SIL 3

90 % - < 99 % SIL 2

SIL 3

SIL 4

≥ 99 %

SIL 3

SIL 4

SIL 4

IEC 61508-2, Table 3

Nov 04, 2014