Omron NX-SL series

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4 Safety Function Blocks
NX-series Safety Control Unit Instructions Reference Manual (Z931)
4
SF_GuardMonitoring
 Error Detected
• Specific errors are detected for the SAFEBOOL external signal input. According to EN ISO
13849-1 (safety guards that have two switches), mechanical settings and open/close switch set-
tings are combined. According to EN ISO 13849-1, the offset in the response times of both
mechanical switches is monitored as the discrepancy time. The offset is treated as detection of an
application error, i.e., an error created by the application.
• An error is detected when the offset between the first input and second input for S_GuardSwitch1
or S_GuardSwitch2 is larger than the value of the DiscrepancyTime input. The Error output is set
to TRUE.
• If Reset is already TRUE when the Wait for Reset state is entered, this FB detects the undetected
change to TRUE as an error.
 Reset Operation for Errors
• When an error occurs, the S_GuardMonitoring output is set to FALSE.
• If the two inputs S_GuardSwitch1 and S_GuardSwitch2 are bridged, an error is not detected. To
reset the Reset Error state, you must set the Reset input to FALSE.
• The S_GuardSwitch1 and S_GuardSwitch2 inputs must both be set to FALSE to reset a discrep-
ancy time error.
 FB-specific Error Codes
 FB-specific State Codes (No Error)
Instruction Execution Errors
DiagCode (hexadecimal)
DiagCode
(decimal)
Status name Status description and output results
C001 49153 Reset Error When the Wait for Reset state was entered, an
undetected change to TRUE in the Reset input
was detected.
Ready = TRUE
S_GuardMonitoring = FALSE
Error = TRUE
C011 49169 Discrepancytime Error
1
The discrepancy time expired in state 8004.
Ready = TRUE
S_GuardMonitoring = FALSE
Error = TRUE
C012 49170 Discrepancytime Error
2
The discrepancy time expired in state 8014.
Ready = TRUE
S_GuardMonitoring = FALSE
Error = TRUE
DiagCode (hexadecimal)
DiagCode
(decimal)
Status name Status description and output results
0000 0 Idle The FB is disabled (default).
Ready = FALSE
S_GuardMonitoring = FALSE
Error = FALSE