TcpAccept

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Function Block A function block groups an algorithm and a set of private data. It has inputs and outputs. - Performs the accept operation.

Inputs

Input	Data Type	Range	Unit	Default	Description
Execute	BOOL	0, 1	N/A	No default	On the rising edge The transition of a digital signal from low to high. AKA: positive edge., accept a new socket connection.
ListenID	UDINT	N/A	N/A	No default	The ID of a server socket returned by the TcpListen function A function calculates a result according to the current value of its inputs. A function has no internal data and is not linked to declared instances. block.

Outputs

Output	Data Type	Description
Done	BOOL	If TRUE, the command completed successfully.
Error	BOOL	If TRUE, an error has occurred.
ErrorID	DINT	Indicates the error if Error output is TRUE. See the table in Search IndexFile and TCP/IP Function Block ErrorIDs.
ID	UDINT	Either: ID of a new client socket accepted. Invalid ID if no new connection.

Remarks

It is possible that the socket becomes invalid if an error occurs in the TCP connection after this function block is called.
Use the TcpIsValid function block after TcpSend.
If the socket is no longer valid, close it using the TcpClose function block.

This function block performs the accept operation using default TCP settings.
Use the TcpClose function block to release the socket returned by TcpAccept.

Figure 1: TcpAccept

FBD Language Example

Not available.

FFLD Language Example

Not available.

IL Language Example

Not available.

ST Language Example

(* TcpAccept example *)
CASE StepCounter OF
0:
   Inst_TcpAccept(TRUE, MyListenID);
   StepCounter := StepCounter + 1;
1:
   Inst_TcpAccept(TRUE, MyListenID);
   IF Inst_TcpAccept.Done THEN
      MySocketID := Inst_TcpAccept.ID;
      Inst_TcpAccept(FALSE, 0);
      StepCounter := StepCounter + 1;
   END_IF;
END_CASE;