Replacement Procedure Of The Cpu Module Battery - Mitsubishi MELSEC User Manual

11
MAINTENANCE AND INSPECTION

11.3.2 Replacement Procedure of the CPU Module Battery

Replace the battery by the following procedure when the Q6BAT battery of the CPU
module comes to the end of its life. The battery replacement can be performed regardless
of the SAFETY MODE or TEST MODE.
The PLC power must be on for 10 minutes or longer before dismounting the battery.
Data in the memory are backed up for a while by a capacitor even after the battery is
removed. However, since data in the memory may be erased if the time for replacement
exceeds the backup time shown in Table11.4, replace the battery quickly.
Save the error/operation history data
as a file with GX Developer. (*1)
Open the CPU module front cover.
Remove the old battery from its
holder.
Insert a new battery into the holder
in the correct direction. Connect the
lead connector to the connector.
Close the CPU module front cover.
Failure of the replaced battery
11
- 8 11.3 Battery Life and Replacement Procedure
11.3.2 Replacement Procedure of the CPU Module Battery
Battery replacement
Turn off the PLC.
Turn on the PLC.
Monitor
SM51 to verify
ON/OFF.
ON
Monitor
SD52 to check if bit 0 is
ON.
Bit 0 is ON.
Figure 11.2 Replacement procedure for the Q6BAT battery
Table11.4 Backup time
Backup time
3 minutes
*1: The CPU module backs up the error/operation history data with a
battery. In the SAFETY MODE, sequence programs and parameters
are saved in the standard ROM. When replacing the battery, save
the error/operation history data as a backup file with GX Developer.
For details, refer to the GX Developer Version 8 Operating Manual
(Safety PLC).
B A T .
Connector of
CPU module side
OFF
Bit 0 is OFF.
CPU module
B A T .
R E S E T
Connector
of battery side
Completed
P U L L
S TO P
R U N