Mitsubishi MELESEC-ST User Manual page 130

12 TROUBLESHOOTING
RUN LEDs flickering (1s interval)
Change the base module of the slice
module (shown as 1) on the left side
of the left-end slice module (shown
as 2) among those whose RUN
LEDs are flickering (1s interval).
Has the RUN LED turned on?
YES
Completed
12 - 5
(2) When RUN LEDs of multiple slice modules (excluding intelligent
function module) are flickering (1s interval)
RUN ERR RUN ERR RUN
1)
NO
Change the left-end slice module
(shown as 2) among those whose
RUN LEDs are flickering (1s
interval).
Has the RUN LED turned on?
YES
RUN LEDs of
multiple modules
flickering (1s interval)
ERR RUN ERR RUN ERR
2)
NO
Change the base module of the left-
end slice module (shown as 2)
among those whose RUN LEDs are
flickering (1s interval).
Has the RUN LED turned on?
YES
MELSEC-ST
NO
Possible cause is excessive noise.
Connect CR or similar surge
suppressor to noise source.
12 - 5