10 MAINTENANCE AND INSPECTION
10.3.2Battery replacement procedure
(1)CPU module battery replacement procedure
When the CPU module battery has been exhausted, replace the battery with a new one according to the procedure shown below. The PLC power must be on for 10 minutes or longer before dismounting the battery.
Even when the battery is dismounted, the memories are backed up by the capacitor for a while. However, if the replacement time exceeds the guaranteed value specified in the table below, the contents stored in the memories may be erased. To prevent this trouble, replace the battery speedily.
Replacing battery
Turn off the PLC power supply.
.
Remove the CPU module from the base unit.
Backup time by capacitor
Backup time by capacitor[min]
3
Open the cover of the CPU module.
Remove the old battery from its holder.
Insert a new battery into the holder in the correct direction.
Connect the lead to the connector.
Close the cover of the CPU module.
Install the CPU module into the base unit.
Turn on the PLC power supply.
Monitor
SM51 to verify on/off.
ON
Monitor
SD52 to verify the bit number
that is on.
Side of the CPU module
Front
OFF
Bits other than 0 are on.
Bit 0 is on.
The memory card battery is faulty.
The CPU module battery is faulty.Refer to Section 10.3.2 (2).Completion
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