Communication Stops During Operation - Mitsubishi Electric FR-A8NC Instruction Manual

9.3

Communication stops during operation

• Check that the option unit (FR-A8NC) and CC-Link dedicated cables are fitted properly.
(Check for contact fault, break in the cable, etc.)
• Check that the programmable controller program is executed properly.
• Check that data communication has not stopped due to an instantaneous power failure, etc.
LED status
Inverters (FR-A8NC)
Master
unit
Station 1 Station 2
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 
: On, : Off, : Flicker, : Any of on, flicker or off
Station 3
RUN 

Since the L.RUN LEDs of the FR-A8NC on
L.RUN 
station 1 and the FR-A8NC on station 3 are off,

 SD
the station numbers of the inverters set as

RD 
stations 1 and 3 are the same.
L.ERR 
 RUN 
Since the L.RUN and SD LEDs of the FR-
L.RUN 
A8NC on station 2 are off, the transmission
 SD 
speed setting of the FR-A8NC on station 2 is
 RD 
wrong within the setting range (0 to 4).
L.ERR 
 RUN 
Since the L.ERR LED of the FR-A8NC on
L.RUN 
station 3 flickers, the setting switch of the FR-
 SD 
A8NC on station 3 was moved during normal
 RD 
operation.
L.ERR 
Cause
HOW TO CHECK FOR ERROR USING THE LEDS
Corrective action
After correcting the repeated
station numbers of the inverters
using Pr.542 Communication
station number (CC-Link),
switch power on again.
After correcting the transmission
speed setting using Pr.543 Baud
rate selection (CC-Link), switch
power on again.
After returning the setting switch
of the FR-A8NC to the original
position using Pr.542
Communication station
number (CC-Link) or Pr.543
Baud rate selection (CC-Link)
power on the inverter again.
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