FCT_SOCKET: Creation of a New Socket

Function Description

The FCT_SOCKET function creates a new socket and returns its socket number. The socket is a TCP/IP communication entity.

It is created as a STREAM TCP socket with the following options:

SO_LINGER without timeout. This option controls the action taken when unsent data is queued on a socket and a FCT_CLOSE function is performed.
NO_DELAY. The delay acknowledgment algorithm is disabled. Data is sent immediately over the network instead of waiting for the window to be completely full.
KEEP_ALIVE. The connection is kept active by regularly and automatically sending packets on the socket.
REUSEADDR. Authorizes the local port for reuse when a FCT_BIND is called.

The additional parameters and may be configured.

Representation in FBD

Representation in LD

Representation in IL

LD Module_Number

FCT_SOCKET Gest_Index,Management_Param, Socket_Number

Representation in ST

FCT_SOCKET(Module_Number, Gest_Index, Management_Param, Socket_Number);

Description of Parameters

The following table describes the input parameters:

Parameter	Type	Comment
Module_Number	INT	Slot number of network module in rack 0. Low byte is the slot number of network module in rack 0. High byte can be used to extend the number of sockets. 00: Provided for full backward compatibility with applications created on firmware version 3.3 or earlier. 01: Up to 64 sockets can be assigned (firmware version must be higher than 3.3).
Gest_Index	INT	Index of first word in Management_Param array

The following table describes the output parameters:

Parameter	Type	Comment
Socket_Number	INT	Number of socket created if no error has occurred.

The following table describes the input/output parameters:

Parameter	Type	Comment
Management_Param	ARRAY [0... 3] OF INT	Function management array The operation report can have the following values: 16#00: No error. 16#37: The maximum number of sockets has been reached.