Chapter 6. CPU Function
6-10
6.7 Diagnosis of External Device
This flag is provided for a user to diagnose any fault of external device and, in turn, execute halt or warning of the
system. Use of this flag displays faults of external device without any complicated program prepared and monitors
fault location without any specific device (XG5000 and etc) or source program.
1) Detection and classification of faults in external device
(1) The trouble (fault) of external device may be detected by user program and largely divided, depending on the
type, into error and warning; the former requires halt of PLC operation and the latter simply displays the status
while PLC keeps working.
(2) ‘Heavy trouble’ uses ‘ _ANC_ERR’ flag and ‘Light trouble’ uses ‘_ANC_WB’ flag.
2) Heavy trouble of external device
(1) In case of detecting heavy trouble of external device at user program, write error code defined by user at
system flag ‘ANC_ERR’ and turn on _CHK_ANC_ERR flag. If _CHK_ANC_ERR flag is on, at the end of scan,
‘_ANNUN_ER’ bit of ‘_CNF_ER’, system error representative flag, is on and PLC turns off all output of output
module (it can be different according to the setting of basic parameter) and becomes error status (Error LED
flickers with 1s cycle)
(2)
In case of heavy trouble, you can know the reason by checking ‘_ANC_ERR' flag.
(3) To turn off the ERR LED caused by flag detecting heavy trouble of external device, reset or restart PLC
Example)
3) Light trouble of external device
(1) In case of detecting heavy trouble of external device at user program, write error code defined by user at
system flag ‘ANC_WAR’ and turn on _CHK_ANC_WAR flag. If _CHK_ANC_WAR flag is on, at the end of
scan, ‘_ANNUN_WAR’ bit of ‘_CNF_WAR’, system warning representative flag, is on. When light trouble
occurs, LED flickers with 2s cycle.
(2) In case of heavy trouble, you can know the reason by checking ‘_ANC_WAR' flag.
(3) If _CHK_ANC_WAR is off, light trouble status is canceled and Error LED is off.
Example)
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