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9   Inspection and Maintenance
NX-series Analog I/O Units User’s Manual for Analog Input Units and Analog Output Units (W522)
9-1  Cleaning and Inspection
9
9-1-2  Periodic Inspection
Periodic Inspection Items
No.
Inspec-
tion item
Inspection details Criteria Correction
1 External 
power sup-
ply
Is the power supply voltage mea-
sured at the terminal block within 
standards?
Within the power supply 
voltage range
Use a voltage tester to check the power 
supply at the terminals. Take necessary 
steps to bring the power supply within 
the power supply voltage range.
2 I/O power 
supply
Is the power supply voltage mea-
sured at the I/O terminal block 
within standards?
Voltages must be within 
I/O specifications of each 
NX Unit.
Use a voltage tester to check the power 
voltage at the terminals. Take necessary 
steps to bring the I/O power supply within 
NX Unit standards.
3 Ambient 
environ-
ment
Is the ambient operating tem-
perature within standards? 
0 to 55°C Use a thermometer to check the tem-
perature and ensure that the ambient 
operating temperature remains within the 
allowed range of 0 to 55°C. 
Is the ambient operating humid-
ity within standards? 
Relative humidity must be 
10% to 95% with no con-
densation.
Use a hygrometer to check the humidity 
and ensure that the ambient operating 
humidity remains between 10% and 
95%.
Make sure that condensation does not 
occur due to rapid changes in tempera-
ture.
Is it subject to direct sunlight?
Not in direct sunlight
Protect the Controller if necessary.
Is there an accumulation of dirt, 
dust, salt, metal powder, etc.?
No accumulation Clean and protect the Controller if neces-
sary.
Is there water, oil, or chemical 
sprays hitting the Controller?
No spray Clean and protect the Controller if neces-
sary.
Are there corrosive or flammable 
gases in the area of the Control-
ler?
No spray Check by smell or use a sensor.
Is the Unit subject to shock or 
vibration?
Vibration resistance and 
shock resistance must be 
within specifications.
Install cushioning or other vibration and 
shock absorbing equipment if necessary.
Are there noise sources near the 
Controller?
No significant noise 
sources
Either separate the Controller and noise 
source, or protect the Controller.
4 Installa-
tion and 
wiring
Are the DIN track mounting 
hooks for each NX Unit securely 
locked?
No looseness Securely lock the DIN track mounting 
hooks.
Are the cable connectors fully 
inserted and locked?
No looseness Correct any improperly installed connec-
tors. 
Are there any loose screws on 
the End Plates (PFP-M)?
No looseness Tighten loose screws with a Phil-
lips-head screwdriver.
Are the NX Units connected to 
each other along the hookup 
guides and until they touch the 
DIN track?
You must connect and fix 
the NX Units to the DIN 
track.
Connect the NX Units to each other 
along the hookup guides and until they 
touch the DIN track.
Are there any damaged external 
wiring cables?
No visible damage Check visually and replace cables if nec-
essary.