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MELSEC-Q
11 TROUBLESHOOTING
Occurrence
Error
Code
Error Name
Description
Lit LED
Corrective Action
1) 2) 3) 4) 5)
734F
H
Request
message size
setting error
The request message size
specified in the argument
((S2)+0) of the MBREQ
instruction is incorrect.
COM.ERR.
Review the setting of the request
message size.
7351
H
Automatic
communication
function start
interruption
The start of the automatic
communication function was
interrupted due to the
processing of the basic
parameter setting.
COM.ERR.
After turning ON the Automatic
communication parameter setting
request/Automatic communication
start request (Y4), do not turn ON
the Basic parameter setting
request (Y1) until the Automatic
communication operation status
(X6) turns ON.
The automatic communication
function was started or stopped
without the basic parameter
being set.
COM.ERR.
Start or stop the automatic
communication function with
Basic parameter setting existence
(X3) on.
7352
H
Basic
parameter not
set
The automatic communication
function was started when
parameter setting was being
made on GX Configurator-MB
at power-on.
COM.ERR.
When using GX Configurator-MB,
switch the power on and then turn
on Automatic communication
parameter setting
request/Automatic communication
start request (Y4) after Basic
parameter setting existence (X3)
has turned on.
7360
H
Exception
message
reception
When the automatic
communication function or
dedicated instruction is used,
the target slave device
returned an exception code in
reply to the request message
sent by the QJ71MT91.
COM.ERR.
• Refer to the exception code
returned from the target slave
device, and resolve the problem.
• Resolve the problem that
occurred in the target slave
device.
7361
H
Byte count
error
In the automatic
communication function or
dedicated instruction, the
number of bytes in the received
response message is less or
more than necessary.
COM.ERR.
7362
H
Reference
number error
The value of the reference
number in the response
message received by the
dedicated instruction is
incorrect.
COM.ERR.
7363
H
Protocol ID
error
In the automatic
communication function or
dedicated instruction, the
protocol ID of the received
response message is other
than "0: MODBUS
R
protocol".
COM.ERR.
On the target slave side, check
whether the contents of the
returned response message are
correct or not.
(Continued on next page)