Set command

The set command measures Signal-to-Noise Ratio (SNR).

To measure SNR correctly, the Carrier Wave (CW) offset must be +330 kHz for the LTE-M mode and +45 kHz for the Narrowband Internet of Things (NB-IoT) mode.

Syntax:

%XRFTEST=<test>,<operation>,<param0>,<param1>,…,<param4>

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

<test>
3 – RX SNR
<operation>
1 – ON
Note: OFF <operation> is not needed due to automatic stop.
<param0>
3GPP band number. Use 24 for Global Positioning System (GPS) reception.
<param1>
Frequency 100 kHz (that is, 2140 MHz is expressed as 21400)
<param2>
RX signal power at the SiP antenna port

Valid range from −127 dBm to −25 dBm

<param3>
System mode

Valid range 0–1. NB-IoT (0) or LTE-M (1).

<param4>v1.2.xpti_v1.1.x≥1
Enabling AFC correction during SNR test

1 – Enable

0 – Disable

If <param4> is not given, AFC correction is disabled.

Response syntax:

%XRFTEST: <snr>,<antenna_power>

The response parameters and their defined values are the following:

<snr>
Result of the SNR measurement in q4 dB. q4 means that dividing the result by 24 = 16 dB.
<antenna_power>
Measured signal power at the System in Package (SiP) antenna port in q8 dBm. q8 means divided dividing the result by 28 = 256 gives dBm.

The following command example enables the RX SNR measurement and RF receiver for Band 1, 2140.0 MHz, −65 dBm, LTE-M mode, AFC correction enabled:

AT%XRFTEST=3,1,1,21400,-65,1,1
%XRFTEST: 496,-17002
OK
Note: 496/16 = 31 dB and −17002/256 = −66.4 dBm.