Mitsubishi Electric Q01UCPU User Manual page 204

(b) Clearing errors using the special relay (SM) and special register (SD)
Perform the following procedure.
• CPU modules other than the High-speed Universal model QCPU
1.
2.
3.
4.
When the latest error (the error stored in SD0) is cleared, error information (stored in SM0, SM1, SM5, SM16, SD0 to SD26)
are cleared. If more than one error has been detected, information on other errors are also cleared and no longer obtained.
To clear other errors, obtain the past error data from the error history.
• High-speed Universal model QCPU
1.
2.
3.
4.
5.
The High-speed Universal model QCPU can clear errors by storing an error code in SD50. In this case, however, error types
cannot be specified.
(3) Status after error clear
When the CPU module is recovered from errors, the related special relay, special register, and LEDs return to the
status before the errors occurred. If the same error occurs after clearing an error, it is registered in the error
history again.
(4) Precautions
• Since errors with the same message are batch-cleared regardless of their error codes, error codes not
intended may also be cleared.
• To clear more than one annunciator, perform the same number of error clear operations as that of
annunciators that are on.
● When the clear-target error code is stored in the special register, the units digit of the code is ignored.
When the error codes 2410, 2411, and 2412 occur and 2412 is stored in SD50 to clear, other two error codes 2410
Ex.
and 2411 are also cleared.
● Only errors occurred in a CPU module can be cleared.
Since "SP. UNIT DOWN" is an error occurred in the Q bus, the error cause will not be eliminated with the error clear
Ex.
methods explained in this section. To eliminate the error cause, refer to the following.
QCPU User's Manual (Hardware Design, Maintenance and Inspection)
202
Eliminate the error cause.
Store the error code corresponding to the error to be cleared in SD50.
Turn off and then on SM50.
The error is cleared.
Check the continuation error(s) detected in SD81 and SD82. (For the bit pattern, refer to the
QCPU User's Manual (Hardware Design, Maintenance and Inspection).)
Eliminate the error cause(s).
Specify the error(s) to be cleared in SD84 and SD85.
Turn off and then on SM84.
Check the bit(s) corresponding to the cleared error(s) in SD81 and SD82 is off.