11 TROUBLESHOOTING

11.2.16 Flowchart for when UNIT VERIFY ERR. occurs

MELSEC-Q

The following shows the flowchart to be followed when UNIT VERIFY ERR. occurs at PLC power-on or during operation.

UNIT. VERIFY ERR. occurs.

Check the slot where error occurred with the GX Developer.

Is the module of

NO

 

 

 

 

 

 

 

 

 

 

Install the module properly.

 

the applicable slot installed

 

 

 

 

 

 

 

 

 

 

properly?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

YES

 

NO

 

 

YES

 

 

 

 

 

 

 

 

 

 

 

 

Is the "ERR." LED

 

 

 

 

 

 

 

 

turned off?

 

 

 

 

 

 

 

 

 

 

 

Are all the

NO

 

 

 

 

 

 

 

extension cables of the

 

 

 

 

 

 

 

 

 

 

Install the extension cable properly.

 

base module connected

 

 

 

 

 

 

properly?

 

 

 

 

 

 

 

 

 

YES

 

NO

 

 

YES

 

 

 

 

 

 

Is the "ERR." LED

 

 

 

 

 

 

 

 

 

 

 

 

turned off?

 

 

 

 

Proper operation

 

 

 

Replace the applicable module.

 

 

 

 

 

 

 

 

 

 

 

 

Error detection

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Proper operation

 

 

 

Replace the CPU module.

 

 

 

 

 

 

 

 

 

 

 

 

Error detection

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Proper operation

 

 

 

Replace the applicable

 

 

 

base unit.

 

 

 

 

 

 

 

 

Error detection

Hardware fault

Please consult your local Mitsubishi service center or representative, explaining a detailed description

of the problem. Completion

11 - 16

11 - 16