Chapter 10 Maintenance
10-1
Chapter 10 Maintenance
Be sure to perform daily and periodic maintenance and inspection in order to maintain the PLC in the best conditions.

10.1 Maintenance and Inspection

The I/O module mainly consist of semiconductor devices and its service life is semi-permanent. However, periodic inspection is
requested for ambient environment may cause damage to the devices. When inspecting one or two times per six months, check
the following items.
Check Items Judgment Corrective Actions
Temperature 0 ~ + 55°C
Humidity 5 ~ 95%RH
Adjust the operating temperature and humidity with the
defined range.
Ambient
environment Vibration No vibration Use vibration resisting rubber or the vibration prevention
method.
Play of modules No play allowed Securely enrage the hook.
Connecting conditions of
terminal screws No loose allowed Retighten terminal screws.
Change rate of input voltage − 15% to 10% Hold it with the allowable range.
Spare parts
Check the number of
Spare parts and their
Store conditions
Cover the shortage and improve the conditions

10.2 Daily Inspection

The following table shows the inspection and items which are to be checked daily.
Check Items Check Points Judgement Corrective
Actions
check for loose mounting screws Screws should not be loose Retighten
Screws
Connecting conditions
of terminal block or
extension cable Check the distance between solderless
terminals Proper clearance should be provided Correct
PWR LED Check that the LED is ON ON(OFF indicates an error) See chapter 11
Run LED Check that the LED is ON during Run ON (flickering indicates an error) See chapter 11
ERR LED Check that the LED is OFF during Run OFF(ON indicates an error) See chapter 11
Input LED Check that the LEO turns ON and OFF ON when input is ON,
OFF when input is off See chapter 11
LED
status
Output LED Check that the LEO turns ON and OFF ON when output is ON,
OFF when output is off See chapter 11