FCT_SHUTDOWN: Disables Transmission on the Socket

Function Description

The FCT_SHUTDOWN function is used to disable either send/receive transmission on the socket.

The TCP window is not changed and incoming data will be accepted (but not acknowledged) until the window is exhausted.

NOTE: the function does not close the socket, and resources assigned to the socket are not freed until the FCT_CLOSE is sent. However you should not attempt to reuse the socket after the FCT_SHUTDOWN function has been executed.

The additional parameters and may be configured.

Representation in FBD

Representation in LD

Representation in IL

LD Module_Number

FCT_SHUTDOWN Socket_Number, Shutdown_Option, Gest_Index, Management_Param

Representation in ST

FCT_SHUTDOWN(Module_Number, Socket_Number, Shutdown_Option, Gest_Index, Management_Param);

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 used (firmware version must be higher than 3.3).
Socket_Number	INT	Socket number
Shutdown_Option	INT	Disable transmission option: 0: No further receives are allowed on the socket. 1: No further sends are allowed on the socket; a FIN message is sent. 2: No further sends or receives are allowed on the socket. This option does the same as both of the previous options together.
Gest_Index	INT	Index of first word in Management_Param array

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#09: The socket number is invalid. 16#16: An argument is not valid. 16#39: The socket is not connected.