You can trigger your RF acquisitions with the following trigger sources:

  • None
  • Digital Edge
  • I/Q Power Edge
  • Software Edge
Note Individual triggers may not support all trigger sources listed here.

None

Signal acquisition starts immediately upon execution of the DSTA Initiate function; no Start or Script Trigger is necessary. This configuration is the default for instruments programmed with DSTA.

Digital Edge

A channel performs an operation when the signal transitions from high to low or from low to high.

A digital signal has two discrete levels: a high level and a low level. When the signal transitions from high to low or from low to high, a digital edge is created. There are two types of edges:

  • Rising—Occurs when the signal transitions from low level to high level
  • Falling—Occurs with a transition from high level to low level

    • Triggers configured to act on a rising or falling edge of a digital signal are called edge triggers. Digital triggering is possible on the RTSI lines, PFI lines, and the PXI Star Trigger line.

    As the figure shows, an edge trigger can be configured to occur either at the place labeled Falling Edge of Signal or Rising Edge of Signal.



    You can configure each named trigger to operate based on a digital edge.

    I/Q Power Edge

    After data has been downconverted and decimated, DSTA calculates the instantaneous power of the I/Q data (I2 + Q2) in the digital downconverter and uses this value as a source for the Reference Trigger for the IF digitizer.

    As shown in the following figure, an I/Q Power Edge Trigger can be configured to occur either at the positive slope or the negative slope.



    Only Reference Triggers may be configured to trigger based on the I/Q power edge.

    Software Edge

    A software trigger is generated internally by a programmatic call to the DSTA Send Software Edge Trigger function and can occur at any time, based upon the conditions specified in the program.

    You can configure each named trigger in DSTA to operate based on a software edge.