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MELSEC-Q
4 MODBUS
R
STANDARD FUNCTIONS
(3) Storage location of exception code and error code
On error completion of processing in the slave (QJ71MT91), an exception code is
sent to the master. (Refer to the "Response message format (when completed
with an error)" given in Section 4.3.1 to 4.3.12.)
The exception code is also stored into the QJ71MT91 buffer memory.
Further, to allow the cause to be indentified in more detail, the error code is
stored into the QJ71MT91 buffer memory.
The exception code and error code can be confirmed in the error log area
(address: CFE
H
to DFF
H
) of the buffer memory.
REMARK
(1) Refer to Section 11.3 for the confirmation method and details of the exception
code and error code.
(2) Refer to Section 4.2 for details of the PDU (protocol data unit).