
Rockwell Automation Publication IASIMP-QS005H-EN-P - April 2016
191
Appendix
B
Safety Output Logic Example for Multiple Output Devices
This GuardLogix® safety logic example illustrates the output logic for a safety zone that has two dual-channel devices that
require separate safety ROUT output instructions.
***************************** Multiple Safety_Contactor_CAT4 Safety Logic *****************************
This Safety Logic Example should only be used and applied in accordance with the
Safety Concepts and Requirements covered in the GuardLogix Controller Systems
Safety Reference Manual (Publication 1756-RM093)
GENERAL OPERATION
This sample code demonstrates how to control multiple sets of redundant safety contactors in series to drop out a individual loads.
These ROUT instructions provide SIL 3 level diagnostics for redundant contactors with auxiliary feedback (EDM).
The ROUT instructions control dual outputs from different Guard I/O Modules.
This Multiple Safety Contactor CAT3_CAT4 Safety Logic includes a single Safety Input Interlock rung that works in
conjunction with the CAT3 and CAT4 safety input device logic routines for this zone.
CONFIGURATION DETAILS
The ROUT instructions are the primary safety instructions within this routine.
The ZoneName_DeviceName ROUT instruction tag names (Zone1_ROBOTCONTACTOR1 and
Zone1_ROBOTCONTACTOR2) identify the specific instruction for the unique safety output devices.
This routine assumes that the auxiliary feedback channels for each device are wired in series to a single input. This is why
the Feedback 1 and 2 tags for each ROUT are identical.
The Fault Reset is assigned to a tag named "Cmd_ZoneName_FaultReset" representing a command triggered by an HMI
or hardwired input. This same Fault Reset tag, "Cmd_ZoneName_FaultReset", will be used on all of the the safety input
and output instructions within it's safety zone.
Safety Input Interlock Rung
This rung illustrates (7) safety device input interlocks that energize the Sts_ZoneName_InputsOK OTE instruction. The
Sts_ZoneName_InputsOK tag is then included in the Output Enable Rung for all ROUTinstructions within the same zone.
0
Sts_Zone1_LOCKINGSW1_InputOK
Sts_Zone1_LOCKINGSW2_InputOK
Sts_Zone1_ESTOP1_InputOK
Sts_Zone1_ESTOP2_InputOK
Sts_Zone1_ESTOP3_InputOK
Sts_Zone1_ESTOP4_InputOK
Sts_Zone1_LC1_InputOK
Sts_Zone1_InputsOK