TcpAccept

Description

This function block performs the accept operation using default TCP settings. You will have to use the TcpClose function block to release the socket returned by TcpAccept.

• 
  
• It is possible that the socket becomes invalid if an error occurs in the TCP connection after this function block is called. You must use the TcpIsValid function block after TcpSend. If the socket is no longer valid then you must close it by using the TcpClose function block.

Figure 8-215: The TcpAccept function block

Related Functions

TcpBinReceive, TcpBinSend, TcpClose, TcpConnect, TcpIsConnected, TcpIsValid, TcpListen, TcpReceive, TcpSend

Arguments

Input

Execute	Description	On the rising edgeA rising edge is the transition of a digital signal from low to high. It is also called positive edge accept a new socket connection
	Data Type	BOOL
	Range	0, 1
	Unit	N/A
	Default	—
ListenID	Description	The ID of a server socket returned by the TcpListen function block
	Data Type	UDINT
	Range	N/A
	Unit	N/A
	Default	—

Output

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

Example

Structured Text

(* 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;