6 F 3 B 0 3 6 2
e.TCP transmission processing example
Ladder program flowchart
TCP transmission processing start
Socket status read/verify
Are bits B and F both 1? | No |
(Is a connection established?) |
|
Yes |
|
Are bits 8 and 9 both 0? | No |
(In neither the RCLOSE nor NOACK |
|
state?) |
|
Yes |
|
|
|
Execute a TCP send request |
|
(CMD = 0037H). |
|
|
|
Hold the input of function block in the on state until the SEND instruction completes.
Instruction completion
Error result
The processing in this section can be performed at this stage or at the point the instruction terminates abnormally.
A connection has not been established with the specified TCP socket. (Open processing is required.)
The specified TCP socket is either:
•Closed by the remote port, or
•Not responding.
(The socket must be closed by the local port.)
Verify the status
Normal complete?
Yes
No
An error occurred in transmission processing.
Transmission from the specified socket is not possible.
Handle the error according to the completion and socket status.
Terminate TCP transmission
processing
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