Omron CJ2 CPU UNIT - Page 213

6-17
6 Troubleshooting
CJ2 CPU Unit Hardware User’s Manual
6-1 CPU Unit Errors
6
6-1-7 Handling Errors
z Recovery Processing Flow
z Error Causes and Remedies
If the measures described above do not clear the error, take the measures shown in the following
table.
*1 This refers to errors caused by data corruption. SRAM is used for the CPU Unit user memory. SRAM is
affected by cosmic rays (neutrons) and naturally occurring radiation, so data can become corrupted.
Suspected cause of
error
Confirmation method Remedy
Prevention of recur-
rence
Unit failure
• Memory element failure
• Memory peripheral cir-
cuit failure
A memory error has prob-
ably occurred in the follow-
ing cases.
• If the error is not cleared
when the CPU Unit is
restarted after the
recovery measures
• If the error occurs fre-
quently
• If the condition improves
when the Unit is
replaced.
Replace the CPU Unit. Determined by the cause
of the failure.
A conductive object has
gotten inside.
Check for conductive
objects.
Clean the inside of the
Unit with an air blower or
replace the CPU Unit.
Do not do any metal work-
ing in the vicinity of the
control panel. Close the
control panel.
Noise
• Data corruption in mem-
ory
• Microcomputer malfunc-
tioning
• Memory write circuit
malfunctioning
When the CPU Unit is
restarted after the recov-
ery measures, the error
will either be cleared or
will continue to occur.
Check whether errors
become less frequent
after the Unit is replaced.
Take measures against
noise. (Investigate the
path of entry.)
•FG
• Power lines
Same as at the left.
Software error
*1
None None None
Memory error
Check the error
status.
Implement the
remedy.
Is the error cleared?
Yes
No
Replace the Unit.
Restart the System.