3 Part Names and Functions
3 - 48
NX-series Safety Control Unit User’s Manual (Z930)
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 9 Troubleshooting.
I/O power supply monitoring monitors the voltage range of the I/O power supply to ensure the operation
of the internal circuits. If a voltage that is outside of the specified range is detected, all safety output ter-
minals for the Unit are turned OFF.
At this time, an I/O Power Supply Voltage Error occurs. To troubleshoot errors, refer to Section 9 Trou-
bleshooting.
This function does not work if all of the terminals are set as unused terminals.
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.
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.
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.
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 sup-
ply OFF circuit test is performed when the I/O power supply is turned ON.
Safety Output Terminal Short Detection
I/O Power Supply Monitoring
I/O Power Supply OFF Circuit Test (Internal Circuit Diagnosis)