TcpConnect

Description

This function block creates a new socket and performs the connect operation using default TCP settings, and a specified server address and port. You will have use the TcpClose function block to release the socket returned by TcpConnect.

• 
  
• It is possible that the function returns a valid socket ID even if the connection to the server is not yet actually performed. After calling this function, you must use the TcpIsConnected function block to know if the connection is ready.

Figure 7-220: The TcpConnect function block

Related Functions

TcpAccept, TcpBinReceive, TcpBinSend, TcpClose, 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 request to connect a socket to a server.
	Data Type	BOOL
	Range	0, 1
	Unit	N/A
	Default	—
Address	Description	The IP Address of the remote server.
	Data Type	STRING
	Range	N/A
	Unit	N/A
	Default	—
Port	Description	The network port to use.
	Data Type	DINT
	Range	N/A
	Unit	user units
	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 the new client socket
	Data Type	UDINT

Example

Structured Text

(* TcpConnect example *)
CASE StepCounter OF
0:
   Inst_TcpConnect(TRUE, '192.168.1.1', 1234);
   StepCounter := StepCounter + 1;
1:
   Inst_TcpConnect(TRUE, '192.168.1.1', 1234);
   IF Inst_TcpConnect.Done THEN
      MySocketID := Inst_TcpConnect.ID;
      Inst_TcpConnect(FALSE, '', 0);
      StepCounter := StepCounter + 1;
   END_IF;
END_CASE;