Table Of Contents
UDP Multicast Open (Read/Write) (G Dataflow)
Subscribes to a UDP multicast group with read and write access on the port you specify.
Programming Patterns
net address
The network address of a network interface on the local device where this node listens for data.
- If you do not specify a network address, the OS picks a default interface that is used to receive data. If the node is read/write and you do not specify a network address, this node sends and receives data on all interfaces.
- If you have more than one network interface on your server, such as two Ethernet interfaces, you can specify an address so that this node listens for data only on the interface with that address.
- If this input is on a node with write access, this is also the interface on which data will be transmitted.
Default: 0
port
The local port you want to use to send and receive UDP datagrams.
multicast address
IP address of the multicast group you want to join. This terminal is required and returns an error if you do not specify an address. Multicast group addresses are in the 224.0.0.0 to 239.255.255.255 range.
Default: 0
time-to-live
Number of routers, minus 1, to forward a datagram. The time-to-live (TTL) value applies to all datagrams sent using this socket. Setting a larger TTL value than your application requires can cause high network utilization. The following table lists the action that occurs to a multicast datagram when you specify a value for the time-to-live input.
| 0 | The datagram remains on the host computer. |
| 1 | Hubs/repeaters and bridges/switches forward the datagram to every client on the same local subnet that subscribes to that IP address. Routers do not forward the datagram. |
| >1 | Sends the datagram, and routers forward it through the number of layers that time-to-live is set to, minus 1. Because most routers are not configured by default to forward multicast packets, you may need to configure your router to forward multicast packets. |
Default: 1
error in
Error conditions that occur before this node runs.
The node responds to this input according to standard error behavior.
Standard Error Behavior
Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.
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 port the operating system determines is valid for use.
The following table lists valid port numbers as defined by the Internet Assigned Numbers Authority (IANA).
| Type | Range |
|---|---|
| System/Well-Known Ports | 0 through 1023 |
| User/Registered Ports | 1024 through 49151 |
| Dynamic/Private Ports | 49152 through 65535 |
error out
Error information.
The node produces this output according to standard error behavior.
Standard Error Behavior
Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.
Where This Node Can Run:
Desktop OS: Windows
FPGA: Not supported
Web Server: Not supported in VIs that run in a web application