Set command

The set command executes a Global Navigation Satellite System (GNSS) Signal-to-Noise Ratio (SNR) test.

GNSS L1 frequency is 1575.42 MHz. This test expects the Carrier Wave (CW) in the signal generator to be 1575.750 MHz, which means that the offset is 330 kHz. The measurement duration is 1 ms.



The set command parameters and their defined values are the following:

1 – ON
Note: OFF <operation> is not needed due to automatic stop.
RX signal power at the System in Package (SiP) GNSS port
Valid range from −127 dBm to −25 dBm or 0 = default gain −105 dBm
<param1> v1.2.x pti_v1.1.x≥1
AFC correction
1 – Enable AFC correction in measurement
0 – Disable AFC correction in measurement
<param2> v1.2.x pti_v1.1.x≥1
Frequency. Manually give RF frequency for nRF9160 in 100 kHz format. Accepted value is +/- 10 MHz from the default GNSS frequency of 1575.42 MHz. Set the signal generator to f = <param2> + 330 kHz.
Note: If <param2> is not given, nRF9160 uses the default GNSS L1 frequency 1575.42 MHz.
Note: It is recommended to set the signal level defined in the GNSS SNR ON parameters to the expected signal level at the GNSS antenna port of the nRF9160 SiP.

Response syntax:

%XRFTEST: <snr>,<antenna_power>

The response parameters and their defined values are the following:

The result of the SNR measurement in q4 dB. q4 means that dividing the result by 24 = 16 gives dB.
Measured signal power at the SiP GNSS port in q8 dBm. q8 means that dividing the result by 28 = 256 gives dBm.

The following command example executes a GNSS SNR test at –80 dBm level with AFC disabled:

%XRFTEST: 364,-20506
Note: 364/16=22.75dB. –20506/256=–80.1dBm.

The following command example executes an GNSS SNR test for –80 dBm. AFC correction is enabled and uses the result of the previous AFC measurement or AFC set. Instead of the default, the receiver frequency is set to 1575.0 MHz:

%XRFTEST: 364,-20506