Rockwell Automation AADvance Controller Solutions Handbook - Manual (Page 31)

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Document: 553631
(ICSTT-RM447J_EN_P) Issue: 09:
1-19
The physical network is considered a "Black Channel" so the design of the Ethernet
network and the equipment used does not impact the SIL rating of the
communications interface, but the design of the network does affect the reliability of
the network and does impact the spurious trip rate. SNCP Network data can be
combined on a common network resulting in safety and non-safety data sharing in a
common physical network; this does not compromise the SIL rating of the network
but again does introduce failure modes and possibly security risks which can increase
the spurious trip rate, careful consideration should be given to the network topology
during the applications specification and design phase.