Communication Stops During Operation - Mitsubishi FR-A7NC Instruction Manual

9.3 Communication Stops During Operation

• Check that the option unit (FR-A7AC) and CC-Link dedicated cables are fitted properly.
(Check for contact fault, break in the cable, etc.)
• Check that the PLC program is executed properly.
• Check that data communication has not stopped due to an instantaneous power failure, etc.
LED States
Inverters (FR-A7NC)
Master
Unit
Station 1 Station 2 Station 3
RUN RUN
L.RUN L.RUN
SD * SD
RD RD
L.ERR L.ERR
RUN RUN
TIME
L.RUN L.RUN
LINE
SD SD
or
RD RD
TIME
L.ERR L.ERR
LINE
RUN RUN
L.RUN L.RUN
SD SD
RD RD
L.ERR L.ERR
RUN Since the L.RUN LEDs of the FR-
L.RUN A7NC on station 1 and the FR-A7NC
SD * on station 3 are off, the station
RD numbers of the inverters set as
L.ERR stations 1 and 3 are the same.
RUN Since the L.RUN and SD LEDs of the
L.RUN FR-A7NC on station 2 are off, the
SD transmission speed setting of the FR-
RD A7NC on station 2 is wrong within the
L.ERR setting range (0 to 4).
RUN
Since the L.ERR LED of the FR-A7NC
L.RUN
on station 3 flickers, the setting switch
SD
of the FR-A7NC on station 3 was
RD
moved during normal operation.
L.ERR
HOW TO CHECK FOR ERROR
Cause
After correcting the repeated
station numbers of the
inverters using Pr. 542 CC-
Link station number, switch
power on again.
After correcting the
transmission speed setting
using Pr. 543 CC-Link baud
rate, switch power on again.
After returning the setting
switch of the FR-A7NC to the
original position using Pr. 542
CC-Link station number or Pr.
543 CC-Link baud rate power
on the inverter again.
: On, : Off, : Flicker, *: Any of on, flicker or off
USING THE LEDS
Corrective Action
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