SARA-R4 series - System Integration Manual
UBX-16029218 - R06
Product testing
Page 89 of 102
5.2
Test parameters for OEM manufacturer
Because of the testing done by u-blox (with 100% coverage), an OEM manufacturer does not need to repeat
firmware tests or measurements of the module RF performance or tests over analog and digital interfaces in their
production test.
However, an OEM manufacturer should focus on:
Module assembly on the device; it should be verified that:
o
Soldering and handling process did not damage the module components
o
All module pins are well soldered on device board
o
There are no short circuits between pins
Component assembly on the device; it should be verified that:
o
Communication with host controller can be established
o
The interfaces between module and device are working
o
Overall RF performance test of the device including antenna
Dedicated tests can be implemented to check the device. For example, the measurement of module current
consumption when set in a specified status can detect a short circuit if compared with a “Golden Device” result.
In addition, module AT commands can be used to perform functional tests on digital interfaces (communication
with host controller, check SIM interface, GPIOs, etc.) or 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 typically to compare the signal quality with a “Golden Device” in a location with excellent
network coverage and known signal quality. This test should be performed after data connection has been
established.
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 functionality of communication with host controller, SIM card as well as power
supply. It is also a means to verify if components at antenna interface are well soldered.
5.2.2
RF functional tests
The overall RF functional test of the device including the antenna can be performed with basic instruments such
as a spectrum analyzer (or an RF power meter) and a signal generator with the assistance of AT+UTEST
command over AT command user interface.
The AT+UTEST command provides a simple interface to set the module to Rx or Tx test modes ignoring the LTE
signaling protocol. The command can set the module into:
transmitting mode in a specified channel and power level in all supported modulation schemes and bands
receiving mode in a specified channel to returns the measured power level in all supported bands
See the
SARA-R4 series
[2] and the
End user test Application Note
[14], for the
AT+UTEST command syntax description and detail guide of usage.
