Mitsubishi MELSEC-Q Series User Manual page 248

13 TROUBLESHOOTING
Description of problem
Unable to communicate from a local station (remote
register RWw) to the master station (remote register
RWr).
A local station does not operate at the specified
number of occupied stations.
Unable to stop data link.
Unable to restart data link.
The remote station/local station/intelligent device
station/standby master station does not start up.
Faulty stations cannot be detected.
The local station/standby master station does not
start up and the "ERR." LED turns on.
Faulty stations are generated depending on
transmission rate.
When a dedicated instruction is executed, the
abnormal completion bit turns on.
The remote device station is not operating normally.
When multiple remote stations are powered off at
156 kbps, the "L RUN" LED goes off temporarily.
CC-Link cannot be started automatically.
The abnormal completion bit turns on when the
dedicated instruction (RLPASET) is executed.
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Check item
Is the corresponding station set as a reserved
station?
Are there any overlap station numbers?
Do the settings match?
Is QJ61BT11 of function version A set to occupy 2
or 3 stations?
Is the data link stop (SB0002) turned on?
Has an error occurred?
Is the data link restart (SB0000) turned on?
Has an error occurred?
Is the corresponding station disconnected?
Do the parameters for the number of modules and
station information match the settings of the
modules that do not start up?
Are there any overlap station numbers?
Is the station set as an error invalid station?
Is the station number overlapped elsewhere?
Check that the station number of the local station
(including the number of occupied stations) is not 65
or more.
Check that the parameter of the master station that
will return to the system by the standby master
function has not been rewritten.
Can the faulty station be identified using the other
station data link status (SW0080 to SW0083)?
If the transmission rate is reduced to a lower level
such as 156 kbps, can communication be
performed without producing an error?
Has an error occurred?
Are there any errors in the initial settings of the
remote device station?
What is the setting for the retry count?
Has a value been set for the intelligent function
module switch setting?
Is the switch 4 setting of the intelligent function
module switch settings correct?
Are the various settings specified by the RLPASET
instruction correct?
Has the parameter setting method been changed
without turning the power supply to the PLC system
off and back on, or resetting the PLC CPU?
MELSEC-Q
Check procedure
• Check the parameters.
• Check the reserved station specified status
(SW0074 to SW0077).
• Check the station number setting.
• Check the loading status (SW0069).
• Check the station number overlap status
(SW0098 to SW009B).
• Check the loading status (SW0069).
• Check the station number overlap status
(SW0098 to SW009B).
• Check the loading/parameter consistency status
(SW009C to SW009F).
• Set it to occupy 1 or 4 stations.
• Check the sequence program.
• Check the automatic refresh parameter settings.
Check the data link stop result (SW0045).
• Check the sequence program.
• Check the automatic refresh parameter setting.
Check the data link restart result (SW0041).
• Check the cable connection visually or with a line
test.
• Check the parameters (for local station).
• Check the operation status of the PLC CPU in the
corresponding station.
Check the parameters.
Check the station number setting.
Check the parameters.
Check the station number setting.
Check the station number setting switches and
parameter of the local station/standby master
station.
Check the parameter of the master station.
• Check the switch settings for the faulty station.
• Check that the cable is properly wired.
• Check that the shield of the cable is grounded.
• Connect the terminal resistor that matches the
cable type used to the terminal stations located
at each end of the CC-Link system.
• Check the error code for the PLC CPU.
• Check the error code for the master station.
• Check the operation status of the PLC CPUs for
both the master station and the corresponding
local station.
• Check the parameters.
• Check the sequence program.
• Increase the transmission rate.
• Reduce the retry count.
Disable the intelligent function module switch setting
of GX Developer.
Set switch 4 of the intelligent function module switch
settings of GX Developer to 0100
• Check the error code for the PLC CPU.
• Check the error code for the master station.
• Check the operation status of the PLC CPU for
the master station.
Turn the power supply to the PLC system off and
back on, or reset the PLC CPU.
.
H
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