FB_IpOpen
The function block is required for opening a TCP/IP connection from the PLC controller. In this case is the controller is the client that actively establishes a connection to a TCP/IP server. With a positive edge of bStart a connection to a server with the IP address from sRemoteIpAddr is established. The recipient port number was specified when the session was started (see FB_IpStartSession). The sender port number is issued by the controller and can be read from iPortNo. The sender port number is required for sending (see FB_IpSend). bBusy is set as long set as the function block is active. If bBusy is reset and bError is FALSE the TCP/IP connection was terminated successfully and data can be sent or received.
INPUT
VAR_INPUT
bStart : BOOL;
iSession : WORD;
sRemoteIPAddr : STRING(15);
END_VAR
bStart: A rising edge activates the function block.
iSession: Is linked with the session number from function block FB_IpStartSession.
OUTPUT
VAR_OUTPUT
bBusy : BOOL;
bError : BOOL;
iErrorId : WORD;
iPortNo : WORD;
END_VAR
bBusy: This output remains TRUE until execution of the command is complete.
bError: This output is switched to TRUE as soon as an error occurs during the execution of a command. The command-specific error code is contained in iErrorId.
iErrorId: Contains the command-specific error code of the most recently executed command (see table).
iPortNo: TCP port number that was allocated when the TCP/IP connection was opened (local port number).