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Appendix
A-6
A.1.4 LED indication specification during power on
This module performs self-diagnosis through self-H/W check and CPU and interface of PLC.
When self and PLC CPU interface checks are OK, after LED ‘0’ - ‘5’ become On in sequence, RS-232C channel LED
and RS-422 channel LED become On, and ‘RUN’ LED becomes On, then normal operation starts. If after power on
error occurs during the self-diagnosis, SYS-ERROR LED blinks, and LED of error occurrence item lights according to
error code. For the details, see ‘9.2 Diagnosis during power on’.