119 
 
6.4 Canceling of Errors 
 
Q series CPU module can perform the cancel operation for errors only when the 
errors allow the CPU module to continue its operation. 
To cancel the errors, follow the steps shown below. 
 
1) Eliminate the cause of the error. 
2) Store the error code to be canceled in the special register SD50. 
3) Energize the special relay SM50 (OFF 
 ON). 
4) The error to be canceled is canceled. 
 
After the CPU module is reset by the canceling of the error, the special relays, 
special registers, and LEDs associated with the error are returned to the status 
under which the error occurred. 
If the same error occurs again after the cancellation of the error, it will be 
registered again in the error history. 
 
When multiple enunciators(F) detected are canceled, the first one with No. F only 
is canceled. 
 
Refer to the following manual for details of error canceling. 
 
QCPU User's Manual (Function Explanation, Program Fundamentals 
 
POINT 
 
(1)  When the error is canceled with the error code to be canceled stored in 
the SD50, the lower one digit of the code is neglected. 
(Example) 
If error codes 2100 and 2101 occur, and error code 2100 to cancel error 
code 2101. 
If error codes 2100 and 2111 occur, error code 2111 is not canceled 
even if error code 2100 is canceled. 
(2)   Errors developed due to trouble in other than the CPU module are not 
canceled even if the special relay (SM50) and special register (SD50) 
are used to cancel the error. 
(Example) 
Since "SP. UNIT DOWN" is the error that occurred in the base unit 
(including the extension cable), intelligent function module, etc. the error 
cause cannot be removed even if the error is canceled by the special 
relay (SM50) and special register (SD50). 
Refer to the error code list and remove the error cause.