11 - 2 11 - 2
MELSEC-Q
11 TROUBLESHOOTING
No.
Symptom
Check Item
Corrective Action
Reference
Section
Check if the MODBUS
R
device
assignment parameter setting, error
completed (X9) is on.
Refer to "MODBUS
R
device assignment
parameter setting, error completed (X9)
turned on."
This section
(2)-6
Check if the automatic communication
error status (X7) is on.
Refer to the automatic communication
operation status storage area [0C20
H
to
0C23
H
], identify the parameter number
where the error occurred, confirm the
error code stored in the corresponding
automatic communication error code
storage area [0C28
H
to 0C67
H
] or the
exception code from the target slave,
and take corrective action.
Turn off the COM. ERR. LED.
Section 11.3.1
When the dedicated instruction is used,
check it for an error.
Refer to "Dedicated instruction failed.".
Turn off the COM. ERR. LED.
This section
(3)-2
Check the error code in the error log.
Take the corresponding corrective
action.
Turn off the COM. ERR. LED.
Section 11.3
3 COM.
ERR.
LED
turned on.
Refer to "Communication with target device cannot be made even though each
parameter setting is completed.".
This section
(3)-6
Set the basic parameters from GX
Configurator-MB or from the sequence
program.
Chapter 7
Chapter 8
Section 9.1.1
Check the basic parameter setting.
In the setting of intelligent function
module switch 2 (communication
condition setting) - b0: Basic parameter
starting method, select "OFF: Start with
the default parameters".
Section 6.6
4 INIT. LED does
not turn on.
Check if the basic parameter setting,
error completed (X2) is on.
Refer to "Basic parameter setting, error
completed (X2) turned on.".
This section
(2)-3
When using the automatic
communication function
Refer to "Automatic communication
parameter setting, error completed (X5)
turned on." or "Automatic
communication operation status (X6)
does not turn on.".
This section
(2)-5, (2)-7
When using dedicated instruction
Refer to "Dedicated instruction is not
executed.".
This section
(3)-1
When using slave function
Refer to "Slave function of QJ71MT91
does not return response message to
request message.".
This section
(3)-3
5 OPEN LED does
not turn on.
The SD LED does
not flicker during
data transmission.
The RD LED does
not flicker during
data reception.
When using GX Developer connection Refer to "GX Developer cannot be
connected.".
This section
(3)-4
11