10 MAINTENANCE AND INSPECTION

MELSEC-Q

(2) SRAM card CPU module battery replacement procedure

Replace the SRAM card battery in the following procedure.

POINTS

Replace the battery while paying attention to the following.

(a)To back up the data, replace the SRAM card battery with the PLC power supply ON and the SRAM card installed.

(b)Start replacement after backing up the CPU module data using GX Developer.

(c)Since replacement is made with the PLC power supply ON, take extreme care not to get an electric shock.

(d)When dismounting or mounting the battery holder on the SRAM card, take care so that the battery does not come out of the battery holder.

(e)When replacing the battery with the PLC power supply OFF, always back up the data before starting replacement.

[Battery replacement procedure]

1)Back up the SRAM card data using GX Developer.

2)Replace the battery.

3)Write the backed up data from GX Developer to the memory card.

Replacing battery

Open the front cover while the

PLC power supply is on.

Using a flat screw-driver, slide the battery holder's locking switch away from the "LOCK" position.

Remove the battery holder from the SRAM card.

Remove the old battery from its holder.

Battery holder

Insert a new battery into the holder in the correct direction.

"RELEASE" position

Push the battery holder all the way into the memory card, and confirm that the battery holder's locking switch is set to the "LOCK" position.

Monitor

SM52 to verify on/off.

ON

Monitor

SD52 to verify the bit number

that is on.

'+' sign

OFF

Bit 0 is on.

 

 

A bit other than 0 is on

 

 

 

 

 

 

The CPU module battery is faulty.

 

 

 

 

 

 

 

 

 

 

Bit 1 or 2 on:

 

 

 

 

 

 

 

 

 

 

 

 

 

Memory card A battery is faulty.

 

 

 

Completion

 

 

 

 

 

 

 

Refer to Section 10.3.2 (1).

 

 

 

 

 

 

 

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