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MELSEC-F
TROUBLESHOOTING
11
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11.5.2 Receiving errors during fixed buffer communication
(common to procedure exist and no procedure)
POINT
Perform error code reading while the connection is open.
NO
YES
1)
NO
YES
Receiving error
Check the open status of the
connection with an external device.
NO
YES
Execute the open processing of the
applicable connection.
(For details, see Section 5.6.)
Read the open abnormal code (BFM
#124, 134...) of the communication status
storage area and check that no errors
have occurred.
Have parameter errors
occurred?
Fix the error according to the parameter
error code (see Section 11.4).
Read the content of the communication
abnormal code storage area (BFM #125,
135...) corresponding to the fixed buffer
of the buffer memory and check whether
or not a communication error has occurred.
Has a
communication error occurred in the
error log area?
Fix the error according to the
communication error code in the error log
area (see Section 11.4).
NO
YES
Check that "receive" is set in the parameter
open settings.
Receive is set
Change parameters to "receive".
NO
YES
Do the expected length
of data to be received and
the amount of data actually
received match?
Are the corresponding
connection LEDs (C1-C8) lit?
If the amount of actually received data is
smaller than the length of data expected to
be received, the subsequent processing
must allow reception of the remaining data.
If the amount of actually received data is
larger than the length of data expected to
be received, the subsequent data should
be treated as the next request message or
as unnecessary data.
(See NOTE in 11.4.4 section for further
details.)
1)
