Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 1100

• The following figure shows the timing of receive processing using the SP.SOCSND instruction.
Open completion signal
(SD1504.n)
Sequence scan
SP.SOCSND instruction
Completion device (d)
Completion status
indication device (d)+1
Even after the completion device turns on, data may be sent continuously. Check the completion of the send processing on
the receiving side.
Operation error
Error code Description
(SD0)
3405H The connection number specified by (s1) is a value other than 1 to 16.
Upon completion with an error, the completion status indication device (d)+1 is turned on and an error code is stored in the
completion status (s2)+1.
For the error code stored in the completion status (s2)+1, refer to the following.
 MELSEC iQ-R Ethernet User's Manual (Application)
8 BUILT-IN ETHERNET FUNCTION INSTRUCTIONS
1098
8.2 Socket Communications Instructions
Open Data transmission
processing processing
ON
OFF
0 END 0
Execution of the instruction
OFF
OFF
Sending data
END 0 END
ON
Completed with an error
ON
Completed successfully
1 scan
ACK
(TCP only)
0 END
OFF
OFF