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UDP Multicast Open (UDP Multicast Open (Read/Write)) (G Dataflow)

    Last Modified: March 10, 2017

    Opens a UDP multicast socket with read and write access on the port you specify.

    Programming Patterns

    net address

    Network address to listen on. Specifying an address is useful if you have more than one network card, such as two Ethernet cards, and want to listen only on the card with the specified address. If you do not specify a network address, this node listens on all network addresses. Use the String to IP Address node to obtain the IP network address of the current computer.

    This input supports scalar strings and unsigned 32-bit integers.

    Default: 0



    The local port with which you want to create a UDP socket.


    multicast address

    IP address of the multicast group you want to join. If you do not specify an address, you do not join a multicast group, and the connection this node returns is write only. Multicast group addresses are in the to range.

    Default: 0



    Number of routers, minus 1, to forward a datagram. The time-to-live (TTL) value applies to all datagrams sent using this socket. The following table lists what action occurs to a multicast datagram when you specify a value for the TTL parameter.

    0 The datagram remains on the host computer.
    1 LabVIEW sends the datagram to every client on the same local subnet that subscribes to that IP address. Hubs/repeaters and bridges/switches forward the datagram. Routers do not forward the datagram if the TTL is 1.
    >1 LabVIEW sends the datagram and routers forward it through TTL-1 layers.

    Default: 1


    error in

    Error conditions that occur before this node runs. The node responds to this input according to standard error behavior.

    Default: No error


    connection ID

    A network connection refnum that uniquely identifies the connection. Use this value to refer to this connection in subsequent node calls.


    actual port

    Port number the node used. If the input port is not zero, the output port number equals the input port number. Wire 0 to the port input to dynamically choose an available UDP port the operating system determines is valid for use. As defined by the Internet Assigned Numbers Authority (IANA), valid port numbers are between the range of 49152 through 65535. Well Known Ports are between the range of 0 through 1023 and Registered Ports are between the range of 1024 through 49151. Not all operating systems follow the IANA standard. For example, Windows returns dynamic ports between the range of 1024 through 5000.


    error out

    Error information. The node produces this output according to standard error behavior.

    Where This Node Can Run:

    Desktop OS: Windows

    FPGA: Not supported

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