7. Maintenance and Repair
I/O module maintenance
The routine inspections are recommended to maintain the module in good condition.
The I/O module mainly consists of semiconductor elements. Hence, the life of PLC
depends upon the condition of its semiconductor parts. Regular checks must be carried
out as errors in the elements may occur due to the effect of the surrounding environment.
Refer to the following table for the items to be checked, once or twice in every 6 months.
Loose terminal screw
Input voltage change
Pnet I/F Module 2MLL-PSRA, 2MLL-PSEA User's Guide
0 ~ + 55°C
Adjust the temperature and humidity
5 ~ 95%RH
Use vibration-preventive rubber or
Screws should not
Tighten the loosened screw.
Maintain the change rate within the
Check whether the
Replenish insufficient parts and
conditions of spare
improve the storage condition.
parts are proper.
Adjust the power within the allowable
voltage variance range.
DC 20.4 ~ 28.8V