FB_ClientServerConnection

VAR_INPUT

VAR_INPUT
    sSrvNetID       : T_AmsNetID := '';
    nMode           : DWORD := 0;
    sRemoteHost     : STRING(15) := '';
    nRemotePort     : UDINT;
    bEnable         : BOOL;
    tReconnect      : TIME := T#45s;
END_VAR

sSrvNetID: string containing the Ams network address of the TwinCAT TCP/IP Connection Server. For the local computer (default) an empty string may be specified.

nMode: parameter flags (modes). The permissible parameters are listed in the table and can be combined via an OR operation:

sRemoteHost: IP address (Ipv4) of the remote server as a string (e.g. '172.33.5.1'). An empty string can be entered on the local computer for a server.

nRemotePort: IP port number of the remote server (e.g. 200).

bEnable: as long as this input is TRUE, the system attempts to establish a connection at regular intervals until a connection was established successfully. Once established, a connection can be closed again with FALSE.

tReconnect: cycle time with which the function block attempts to establish the connection. After this time at the latest, the attempt is aborted and a new one is started.

The tReconnect value should not be set too low, since timeout periods of > 30 s may occur in the event of a network interruption. If the value is too low, command execution would be interrupted prematurely, and ADS error code 1861 (timeout elapsed) would be returned instead of the Winsocket error WSAETIMEDOUT.

VAR_OUTPUT

VAR_OUTPUT
    bBusy       : BOOL;
    bError      : BOOL;
    nErrId      : UDINT;
    hSocket     : T_HSOCKET;
    eState      : E_SocketConnectionState := eSOCKET_DISCONNECTED;
END_VAR

bBusy: This output is TRUE as long as the function block is active.

bError: Becomes TRUE as soon as an error has occurred.

nErrID: If the bError output is set, this parameter returns the TwinCAT TCP/IP Connection Server error number.

hSocket: Connection handle for the newly opened local client socket. If successful, this variable is transferred to the instances of the function blocks FB_SocketSend and/or FB_SocketReceive.

eState: Returns the current connection status.

Example of a call in FBD:

PROGRAM MAIN
VAR
    fbClientConnection1     : FB_ClientServerConnection;
    bConnect1               : BOOL;
    bBusy1                  : BOOL;
    bError1                 : BOOL;
    nErrID1                 : UDINT;
    hSocket1                : T_HSOCKET;
    eState1                 : E_SocketConnectionState;
END_VAR

Further application examples (including source code) can be found here: Examples

Requirements