User manual

Publication 1756-RM093F-EN-P - January 2010 15
Safety Integrity Level (SIL) Concept Chapter 1
GuardLogix Architecture
for SIL 3 Applications
The following illustration shows a typical SIL function, including:
• the overall safety function.
• the GuardLogix portion of the overall safety function.
• how other devices (for example, HMI) are connected, while
operating outside the function.
Typical SIL Function
1756-DNB
To Plant-wide Ethernet
SIL 3 GuardLogix System
Programming Software
HMI
Read-only Access to Safety Tags
Overall Safety Function
1756-L6xS 1756-LSP 1756-ENBT
Switch
Actuator
DeviceNet Safety Network
Sensor
CIP Safety
I/O Module
CIP Safety
I/O Module
CIP Safety I/O Module on
Ethernet Network
CIP Safety
Actuator
Sensor
Actuator
Sensor
SIL 3 Compact GuardLogix System
CIP Safety I/O Module on
Ethernet Network
Compact GuardLogix Controller with 1768-ENBT Module