Table Of Contents
UDP Open (G Dataflow)
Opens a UDP socket to send a datagram to a single receiver on the port or service name you specify. If you want to send a single datagram to multiple receivers in parallel, which may reduce overhead both in code and on the network over sending a datagram to multiple receivers serially, use the UDP Multicast Open node instead of this one.
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.
service name
The name you want to associate with the port number that this node is listening for connections on.
If you specify a service name, this node registers the service name and the associated port number with the NI Service Locator. A client can then use this service name to query the NI Service Locator for the port number associated with that service name. By using registered service names, clients can establish connections with the server without specifying a port number.
What Is the NI Service Locator?
The NI Service Locator stores a list of registered service names and returns a corresponding port number to clients that query for a particular service name.
A client can use a service name to query the NI Service Locator and obtain the port number associated with that service name. Thus, a client does not need to know the port number of a registered service in order to request that service.
The NI Service Locator runs as a background service and requires no user interaction.
Registering Services with the NI Service Locator
Use this input to register a service name and associated port number with the NI Service Locator.
timeout ms
Time, in milliseconds, that the node waits to complete before reporting a timeout error.
Wire a -1 to this input to wait indefinitely.
Default: 25,000 ms
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.