Using Real-time GNSS Signals without a PC Connection

The N7609B software running on a PC needs to be connected via LAN or GPIB to an N5172B EXG or N5182B MXG signal generator in order to make changes in the GNSS simulation settings, make real-time changes to the power level or add impairments to individual satellites, or to simulate scenarios longer than 24 hours using continuous scenario generation. However if real-time changes to the settings are not required, it is possible to simulate real-time GNSS signals without a PC connection by following the procedures in this topic.

The generation of real-time GNSS signals without a PC connection applies only to scenarios that have been previously downloaded and played on a signal generator and stored in its instrument state register as described in these procedures:

Create and Play the Scenario

  1. If not already done, launch the N7609B software and establish a connection to an EXG or MXG.

    If the software is already running, ensure that you are connected to an EXG or MXG.

  2. In the tree view, click on the Instrument node and set the Amplitude, and any other instrument parameters.

  3. Create and save a scenario.

    If needed, refer to the tutorial Creating a Scenario.

  4. In the tree view, click on GNSS.

  5. Click the Scenario File property and use the dialog box launch icon to launch the Open dialog box to navigate to and select the scenario file.

  6. Configure any of the other simulation settings on this window as desired, such as enabling or disabling a GNSS constellation, or applying a relative power scaling to the satellites (the entered value applies to all satellites within a constellation).

  7. Click the State On button to start the real-time signal simulation with the selected settings.

  8. Once the signal has started playing in the instrument, click the State Off button to regain control of the instrument’s front panel.

  9. Close the N7609B software and disconnect the PC from the instrument.

Save the Scenario to the EXG/MXG Instrument State Register

For information on the instrument state registers, refer the X-Series Signal Generator User's Guide.

  1. Press Local to unlock the EXG/MXG front panel.

  2. If there is a need have the GNSS signal start automatically when recalled on the EXG/MXG, perform the following steps:

    1. Press Mode > Real-Time Applications > More > GNSS > GNSS On.
    2. Press RF On/Off to turn the RF Output on (LED below the button is on and RF OFF does not show in the display).

  3. Press Save > Select Reg.

  4. Enter the number of an unused register.

    Even if the current register shows as available, you must enter a number to complete the process.

  5. Press Save Reg to save the current instrument state to that register.

    The menu returns to the previous softkey menu and the Select Reg softkey now shows the entered register number along with (in use).

  6. Press Add Comment to Seq[n] Reg[n], and enter a description for this scenario, such as the name of the scenario file and which constellations are enabled.

  7. Press Enter to finish adding the comment.

Recall the Scenario From the Instrument State Register for Play Back

  1. Press Recall > Select Reg.

  2. Enter the number of the register containing the desired scenario.

  3. Press Enter.