Using the MGT Streaming Generation Example

The MGT streaming Generation example uses an Aurora link to transmit I/Q data from a FlexRIO PXIe-7903 coprocessor to the PXIe-5842, which generates the I/Q data as RF signals.

Complete hardware setup for MGT streaming before using the MGT streaming example programs.
Complete the following steps to navigate and use the LabVIEW example for generation that uses MGT streaming:
  1. Choose your PXIe-5842 instrument in vst resource name and choose the PXIe-7903 as the flexrio resource name.
  2. Define settings for the generation:
    1. Choose VST settings, such as the I/Q rate and carrier frequency.
    2. Choose whether the stream is infinite or finite; if finite, also choose the number of samples to stream.
      A finite stream runs for the number of samples you specify; an infinite stream runs until you stop it manually.
  3. Optional: If desired, set streaming zero waveform length to a positive integer to define the number of zero I/Q samples the PXIe-5842 should generate before it begins generating RF signals from the I/Q data stream.
  4. Run the example, and on the Aurora Config tab, confirm that the following settings match between the PXIe-5842 and the PXIe-7903 coprocessor:
    • line rate
    • packets enabled
    • number of lanes
    • nfc immediate enabled
    • crc enabled
    • endianness

    When you run the example, the MGT streaming bitfile is downloaded to the PXIe-5842, a FlexRIO bitfile is downloaded to the PXIe-7903 coprocessor, and a CW stimulus—in this example, the waveform that will stream from the coprocessor to the PXIe-5842—is written to a buffer in the coprocessor. An Aurora link is then established between the VST and coprocessor. The Aurora Config tab reads and displays the Aurora link status.

    Once the Aurora channels are configured, data begins streaming from the coprocessor to the PXIe-5842. This data fills a buffer on the PXIe-5842, and once the buffer is nearly full, the PXIe-5842 requests that the coprocessor stop sending data and prepares to generate the buffered data.

    An NI-RFSG session begins, and an NI-RFSG start trigger begins generation of the I/Q data as RF signals. When the buffer is nearly empty, the PXIe-5842 requests that the coprocessor transmit more data, and the process repeats.

    Note In this example, the coprocessor sources data faster than the PXIe-5842 can consume it. As a result, the buffer oscillates between the full and empty thresholds when the example is running.
  5. In the Stream Status tab, check the channel up and lane up status to confirm the link is working correctly.
    You can also view other information about the transmission.
    Tip You can calculate data throughput from the I/Q rate as follows:
    Throughput (Gbps) = I/Q Rate (Samples/s) × 4 Bytes Sample × 8 bits Byte

    For example, an I/Q rate of 1.25 GS/s, the VST receive throughput and coprocessor transmit throughput are approximately 40.0 Gbps.

    If channel up indicates the channel is not functioning, check that the hardware setup and cabling are correct.
  6. If you selected an infinite stream, abort the stream by clicking STOP.