Chapter 4. CPU module
4 - 33
4.5.5 History Log-In
The GM6 CPU stores 3 operation histories such as error occurrence, mode change, and power shut-down.
Each history log-in contains the last 16 operation histories.
1) Error occurrence
•
Record occurrence time and error code when an error occurred while the CPU is in RUN mode.
2) Mode change
•
Record the mode change time, operation mode, and restart mode when a operation mode is changed.
3) Power failure
•
Record the occurrence time and total occurrence number when the AC failure occur while the CPU is
in RUN mode.
4.5.6 External Device Error Diagnosis function
Flags are given for the user to implement easily the program in which the error detection of external
devices and system stop and warning are coded. By use of these flags, error indication of external devices
is possible without complex programming and monitoring of the error location can be done without special
tools (GMWIN, etc.) or source programs.
1) External device fault detection and classification
(1) The user program detects external device faults. The faults are classified into fatal fault( error), where
the PLC stops its operation, and ordinary fault(warning), where operation continues.
(2) The flag ANC_ERR[n] is used to indicate error. The flag ANC_WN[n] is used to indicate warning.
2) External Device Fatal-fault (Error) Processing
.
(1) If an error of external device is detected and the error type, where other value than 0 is used, is written
to the system flag ANC_ERR[n], the flag will checked at the time that scan program finishes its
execution. If an error is indicated on the flag, it will be also indicated on the _ANNUN_ER of the
representative system error flag _CNF_ER, the PLC turns all output modules off and the error state
will be same as the PLC self-diagnosis.
(2) The user can know the cause of error by use of the GMWIN, and also by direct monitoring of the flag
_ANC_ERR[n].
(3) As the flag _ANC_ERR[n] has sixteen elements(n : 0 to 15), the user can classify error states largely.
User defined error No. can be written to the elements. A number of 1 to 65535 is usable.
Example)
Error detection
MOV
10
