Omron NX-SL3300 User Manual page 172

4 Safety Control Unit Operation
Safety Output Terminal Short Detection
The safety output terminal short detection prevents the internal circuits of the safety output terminals
from being destroyed if an overcurrent flows due to a ground fault or other cause.
If an overcurrent is detected, the safety output terminal is turned OFF.
At this time, a Short Circuit Detected at Safety Output event will occur. To troubleshoot errors, refer to
Section 12 Troubleshooting on page 12 - 1.
I/O Power Supply Monitoring
I/O power supply monitoring monitors the voltage range of the I/O power supply to ensure the opera-
tion of the internal circuits.
If a voltage that is outside of the specified range is detected, all safety output terminals for the Unit are
turned OFF.
At this time, an I/O Power Supply Voltage Error occurs. To troubleshoot errors, refer to Section
12 Troubleshooting on page 12 - 1.
This function does not work if all of the terminals are set as unused terminals.
I/O Power Supply OFF Circuit Test (Internal Circuit Diagnosis)
The I/O power supply OFF circuit test shuts OFF the I/O power supply and diagnoses the function that
shuts OFF the I/O power supply to see if it is operating correctly.
If an internal circuit fault is detected by this function, all safety output terminals for the Unit are turned
OFF.
This test is executed at the following two times. The I/O power supply OFF circuit test is executed only
once when the Unit power supply is turned ON. The test is not performed again until the Unit power
supply is turned ON again.
l When the Status Changes to Refreshing Status
If the I/O power supply is turned ON before the status changes to refreshing status, the I/O power
supply OFF circuit test is performed when the status changes to refreshing status.
l When I/O Power Supply is Turned ON
If the I/O power supply is turned ON after the status changes to refreshing status, the I/O power
supply OFF circuit test is performed when the I/O power supply is turned ON.
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NX-series Safety Control Unit User's Manual (Z930)