Internet Protocol (IP), User Datagram Protocol (UDP), and Transmission Control Protocol (TCP) are the basic tools for network communication. The name TCP/IP comes from two of the best-known protocols of the internet protocol suite, the Transmission Control Protocol and the Internet Protocol. With TCP/IP you can communicate over single networks or interconnected networks (Internet).
TCP/IP communication provides a simple user interface that conceals the complexities of ensuring reliable network communications. Refer to the Using LabVIEW with TCP/IP and UDP from LabVIEW Help for more information about how TCP/IP communication works.
Use the TCP/IP functions located on the Functions»Data Communication»Protocols»TCP palette for TCP communication in LabVIEW. As with DAQ, instrument, and File I/O communication, the process involves opening the connection, reading and writing the information, and closing the connection.
With most I/O communication, the processor is always the client that initiates a connection to the disk drive server, the external instrument server, or the DAQ board server. With TCP/IP connections, a computer can function either as the client or the server. The following block diagram represents a client application that initiates a connection to a remote server with TCP Open Connection. The server, or daemon, listens for remote connections and responds appropriately.
LabVIEW users can develop custom applications for TCP/IP communication. The programmer is responsible for developing both the client and the server.
Because anyone can initiate a connection to a server, you might want server access control. The following block diagram shows how the server uses the remote address output value of the TCP Listen VI to determine whether a remote client has permission to access the server.