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During RF generation1That is, when GSG is executing a scenario or generating a signal., modify the current signal mode. While GSG is not generating RF, set & store the 1-channel mode satellite identifier and signal mode.

While GSG is not generating RF, modify the current signal mode.

Command Syntax (while not generating RF)

SOURce:ONECHN:SATid <signal_mode_letter><gnss_letter><integer>
SOURce:ONECHN:SATid <gnss_letter><integer>
SOURce:ONECHN:SATid <signal_mode_letter><integer>

Command Syntax (during RF generation, effective as of firmware version 7.0.1)

SOURce:ONECHN:SATid <signal_mode_letter>


<signal_mode_letter>: [M, P, U]

<gnss_letter>: [G, R, E, C, J, I, S]

<integer>: [–7 … 210]

The gnss_letter parameter can be:

  • ‘G’ (or ‘g’) for GPS
  • ‘R’ (or ‘r’) for GLONASS
  • ‘E’ (or ‘e’) for Galileo
  • 'C' (or 'c') for BeiDou
  • ‘J’ (or ‘j’) for QZSS
  • 'I' (or 'i') for IRNSS
  • ‘S’ (or ‘s’) for SBAS

The signal_mode_letter parameter can be:

  • ‘U’ (or ‘u’) for unmodulated GPS signal (carrier only)
  • P’ (or ‘p’) for PRN signal (carrier modulated by PRN sequence, no data messages)
  • ‘M’ (or ‘m’) for modulated signal (normal signal including data messages)
  • The syntax to be used while GSG is not generating any RF allows to omit the signal_mode_letter parameter and instead specify only the gnss_letter parameter followed by an integer. In such case, a modulated signal mode is assumed.

The integer parameter:

  • If the signal mode is modulated or PRN, the parameter <integer> must be a valid satellite id number.
  • For an unmodulated GPS, Galileo, BeiDou, QZSS, or IRNSS signal, the parameter <integer> must not be specified. For an unmodulated GLONASS signal the <integer> parameter specifies the frequency slot [–7 … 6].


Additionally, as of firmware version 7.0.1, it is possible to specify only the signal mode and satellite id. All signals that have been enabled by the source:onechn:signaltype command (or via the front panel) and are compatible to the specified signal mode and satellite id remain set. Incompatible signals are automatically disabled. This syntax is designed to be used together with the ‘source:onechn:signaltype’ command, so that you can first specify the signal mode and satellite ID using the ‘source:onechn:satid’ command and later specify particular signals with the ‘source:onechn:signaltype’ command.

When GLONASS signals are selected along with the modulated mode, the GLONASS frequency slot is determined by the satellite id from the navigation data (specified either using the SOURce:ONECHN:EPHemeris command or from the Ephemeris field in the front panel interface).

For the PRN mode, the frequency slot for GLONASS is determined automatically by a predefined mapping of satellite id to frequency slot.

While the GSG unit is generating RF it is possible to change the signal mode using the reduced command syntax specifying only the desired signal mode. Note that currently it is only possible to change the signal mode to any mode that is ‘lower’ or equal to the initial signal mode used when the signal generator was started. For example, if the signal generator is started in PRN mode it is possible to switch to unmodulated mode and back to PRN mode, but not to modulated mode. If started in modulated mode it is possible to switch between all three signal modes. The signal mode cannot be changed if the signal generator started in unmodulated mode.

Examples (used when the unit is not generating RF)

Set modulated GPS signal with id11:



Set unmodulated GLONASS signal with frequency slot -5:



Examples (used while the unit is generating RF, e.g. executing a scenario)

Set signal mode to unmodulated mode:



Set signal mode to PRN:



Set signal mode to modulated mode: