SARA-G3 and SARA-U2 series - System Integration Manual
UBX-13000995 - R26
Product testing
Page 192 of 217
Component assembly on the device; it should be verified that:
o
Communications with host controller can be established
o
The interfaces between the module and device are working
o
Overall RF performance test of the device including the antenna
Dedicated tests can be implemented to check the device. For example, AT commands can be used to perform
functional tests (communication with host controller, check SIM card interface, check communication between
module and GNSS, GPIOs, etc.), on audio interfaces (audio loop for test purposes can be enabled by the
AT+UPAR=2 command as described in the
u-blox AT Commands Manual
[3]), and to perform RF performance
tests (see the following section 5.2.2 for details).
5.2.1
“Go/No go” tests for integrated devices
A ‘Go/No go’ test is performed to compare the signal quality with a “Golden Device” in a position with excellent
network coverage and after having dialed a call (see the
u-blox AT Commands Manual
[3], AT+CSQ command:
<rssi>, <ber> parameters).
These kinds of test may be useful as a ‘go/no go’ test but not for RF performance measurements.
This test is suitable to check the communication with the host controller or SIM card, the audio and the power
supply functionality and verify if the components at antenna interface are well soldered.
5.2.2
Functional tests providing RF operation
Overall RF performance test of the device including antenna can be performed with basic instruments such as a
spectrum analyzer (or an RF power meter) and a signal generator using AT+UTEST command over the AT
interface.
The AT+UTEST command gives a simple interface to set the module to Rx and Tx test modes ignoring 2G/3G
signaling protocol. The command can set the module:
In transmitting mode in a specified channel and power level in all the supported modulation schemes (single
slot GMSK, single slot 8PSK, WCDMA) and bands 2G, 3G
In receiving mode in a specified channel to returns the measured power level in all 2G/3G supported bands
See the
u-blox AT Commands Manual
[3], for AT+UTEST command syntax description.
See the
End user test Application Note
[28], for AT+UTEST command user guide, limitations and examples
of use.
