
16
Rockwell Automation Publication 1756-RM001I-EN-P - May 2012
Chapter 1
SIL Policy
Simplex Configuration
In a simplex configuration, the hardware used in the safety loop is programmed to
fail to safe. The failure to safe is typically an emergency shutdown (ESD) where
outputs are de-energized.
show a typical simplex SIL loop. The figures
show the following:
•
Overall safety loop
•
ControlLogix portion of the overall safety loop
Use two 1756-EN2TR EtherNet/IP modules for SIL 2 safety loops. Each
redundant input must be routed through separate EtherNet/IP communication
modules.The SIL 2 output and its secondary shutoff must be routed through the
separate 1756-EN2TR EtherNet/IP modules.
SIL 2 I/O modules in the safety loop must meet the requirements specified in
Figure 3 - Fail-safe ControlLogix Ethernet/IP DLR Configuration
SIL 2-certified ControlLogix Safety Loop
Sensor
Actuator
175
6-E
N2T
Overall Safety Loop
I/O
Controller Chassis
Remote I/O Chassis
I/O
EtherNet/IP
Remote I/O Chassis
1756-
EN2
TR
EtherNet/IP
Standard
Communication
1756-
EN2
TR
1756
-E
N2TR
EtherNet/IP
1756-
EN2
TR
Summary of Contents for 1756-L6 Series
Page 24: ...24 Rockwell Automation Publication 1756 RM001I EN P May 2012 Chapter 1 SIL Policy Notes ...
Page 76: ...76 Rockwell Automation Publication 1756 RM001I EN P May 2012 Chapter 6 FLEX I O Modules Notes ...
Page 126: ...126 Rockwell Automation Publication 1756 RM001I EN P May 2012 Appendix D Checklists Notes ...
Page 133: ...Allen Bradley Motors ...