Allen-Bradley 1756-L61S

Rockwell Automation Publication 1756-RM093J-EN-P - April 2018 33
Chapter 4
CIP Safety and the Safety Network Number
Routable CIP Safety Control
System
To understand the safety requirements of a CIP Safety control system, including
the safety network number (SNN), you must first understand how
communication is routable in CIP control systems. The CIP Safety control
system represents a set of interconnected CIP Safety devices. The routable system
represents the extent of potential mis-routing of packets from an originator to a
target within the CIP Safety control system. The system is isolated such that
there are no other connections into the system. For example, because the system
below cannot be interconnected to another CIP Safety system through a larger,
plant-wide Ethernet backbone, it illustrates the extent of a routable CIP Safety
system.
Figure 8 - CIP Safety System Example
Topic Page
Routable CIP Safety Control System 33
Considerations for Assigning the Safety Network Number (SNN) 35
1756-L62S
1756-LSP
1756-DNB
1756-ENBT
1768-PB3
1768-L43S
1769-ECR
Switch
Switch
Router/
Firewall
(1)
CIP Safety I/O
SmartGuard™
1756-IB16
1756-DNB
1756-ENBT
(1) The router or firewall is set up to limit traffic.
1756-OB16
1768-ENBT 1768-ENBT
CIP Safety I/O
CIP Safety I/O
CIP Safety I/O
CIP Safety I/O
CIP Safety I/O
CIP Safety I/O
CIP Safety I/O