This dataflow node connects dataflow wires to asynchronous wires. It accepts dataflow data that it writes into an asynchronous wire.

  • Data in provides dataflow data for the asynchronous node. The default data type for this control is a 32-bit integer, but this terminal and the associated wire adapt to the data type of the input. Integers, fixed-point numbers, Boolean data, and clusters are all accepted.
    Note When an array is wired to Data In, the write accessor node writes all the values into the register, FIFO, or circular buffer.
  • Async wire data supplies the data to the asynchronous wire. The name of this terminal varies.

User-Enabled Terminals

This node has several terminals you can enable by selecting options from the node shortcut menu.

  • Enable specifies that the node only attempts a write operation when the value of enable is TRUE. This control is enabled when you select Add Enable terminal from the Configure Write Accessor dialog box.
  • Success returns the status of this write. This indicator is enabled when you select a FIFO data exchange policy and the wait until write succeeds checkbox is not selected.

Write Accessor Node Details

When you drop the write accessor node on the LabVIEW block diagram, the default data exchange policy is a register. Clicking the glyph on the node launches the Choose Write Policy dialog box in which you can configure the data exchange policy of the asynchronous wire output, the wait behavior (if the data exchange type is a FIFO), and whether you want the enable control enabled.

Reusing a Write Accessor Node

When a write accessor is copied and pasted, you can choose whether to reuse the buffer, which creates a second write accessor node that writes into the same register or FIFO as the first node. Reusing a buffer is useful for writing to the same wire from different cases of a case statement.

Note You cannot reuse write accessor nodes that are configured for circular buffer data exchange policies.

Special Considerations for Single-Cycle Timed Loops

If you wish to use the FIFO data exchange policy inside a single-cycle timed loop, you must uncheck the block until write succeeds checkbox.