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Appendix
G
Using 1794 FLEX I/O Modules and 1756 SIL 2
Inputs and Outputs with 1756 GuardLogix
Controllers to Comply with EN 50156
Topic
Page
SIL 2 Dual Channel Inputs (standard side of GuardLogix controllers)
101
SIL 2 Outputs Using SIL 3 Guard I/O Output Modules
103
SIL 2 Outputs Using 1756 or 1794 SIL 2 Output Modules
103
Safety Functions Within the 1756 GuardLogix Safety Task
104
Dual channel configuration is required for compliance in certain safety-related
applications, including burner-related safety functions. These examples provide
guidelines for satisfying EN50156 SIL 2 dual channel requirements with 1- and
2-year proof test intervals.
SIL 2 Dual Channel Inputs
(standard side of GuardLogix
controllers)
You must implement clear and easily identifiable separation between both input
channels and adhere to all existing SIL 2 requirements as defined in Using
ControlLogix in SIL 2 Applications, publication 1756-RM001.
Figure 27 - SIL 2 Dual Channel Inputs Example F
Channel A
Channel B
Ch0+
Ch0+
+
Ch0-
Ch0-
-
Voltage
Transmitter A
+
Voltage
Transmitter B
-
Rockwell Automation Publication 1756-RM099C-EN-P - May 2015
101