This node reads I/Q data from an asynchronous wire and writes it to a 14-bit DAC. The name of the associated DAC is shown on the node.

By default, the DAC applies a two-bit right shift to each I and Q numerical value before generating it, thus using the most significant 14 bits of each I and Q value. To choose which 14 bits to use, right-click the node and select an option from the Adjust 16-Bit I/Q Data to the 14-Bit DAC submenu.

FIFO Wired to I/Q Parameter Circular Buffer Wired to I/Q Parameter
  • I/Q Data receives the I/Q data from the asynchronous data wire. An I/Q data pair is always packed into a single unsigned 32-bit word with the I data in the upper 16 bits and the Q data in the lower 16 bits. After you wire an asynchronous wire to this input terminal, a gray glyph representing the data exchange policy for the wire appears next to the terminal on the node (). Supported Data Exchange Policy: FIFO, circular buffer.
  • Start Trigger supplies a start trigger to the DAC node. The DAC is configured by a host program, so the DAC cannot start running before that configuration is complete. Click the polarity indicator () to toggle whether the DAC node detects a rising edge trigger (shown) or a falling edge trigger.
  • I/Q Clock supplies the DAC I/Q clock to the asynchronous timing wire. The DAC I/Q Clock controls how I/Q data is produced and is the clock domain in which it is read from the FIFO at the I/Q Data terminal. The name of this terminal varies.
  • Underflow returns whether the DAC failed to read data because the input FIFO is empty. A TRUE is written to the underflow terminal when the DAC attempts to read and fails. If the input FIFO is empty, zeros are used for the I/Q pair. This terminal is not present if the DAC is reading a circular buffer, as shown in the screenshots above.

User-Enabled Terminals

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

Stop Condition—Right-click the node and select Stop Condition»Sample Count or Stop Condition»Trigger Edge to create one of the following two terminals.

  •   Stop Condition»Sample Count specifies the number of samples to generate before stopping the DAC and waiting for another Start trigger.
  •   Stop Condition»Trigger Edge supplies a digital edge Stop trigger to the DAC node. Click the polarity indicator () to toggle whether the DAC node detects a rising edge trigger (shown) or a falling edge trigger.

DAC Node Details

When you drop the DAC node on the LabVIEW block diagram, it is automatically configured for DAC 0. To select the other DAC, right-click the node and select the DAC from the shortcut menu.