Table Of Contents

UDP Write (Text) (G Dataflow)

Last Modified: January 12, 2018

Writes a string datagram to a remote UDP port. To send multicast datagrams, specify the multicast group address in the address input.

Programming Patterns
connector_pane_image
datatype_icon

port or service name

The port or name of the service you want to write to. You can specify a service name to query the NI Service Locator for the port number that the server registered. port or service name can accept a numeric or string input.

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.

datatype_icon

address

The address of the computer where you want to send a datagram. To send multicast datagrams, specify the multicast group address in this input.

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

How Do I Find the Address?

String to IP
datatype_icon

connection ID in

A network connection refnum that uniquely identifies the UDP socket.

datatype_icon

data in

The data to write to another UDP socket.

In an Ethernet environment, restrict the datagram to a reasonable size, such as 1,000 bytes. UDP datagrams must be sent as a single IP packet with no retransmission. If the packet is too large to fit in a single transmission unit of the underlying bus, the receiver might fragment and reassemble it, which increases overhead and the chance that the data could be lost in transit. Specific thresholds vary depending on your network.

datatype_icon

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

datatype_icon

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.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Default: No error

datatype_icon

connection ID out

Same value as connection ID in.

datatype_icon

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.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported

Web Server: Not supported in VIs that run in a web application


Recently Viewed Topics