Some questions about DTM

[Manhull1989]

I have some questions about DTM, can anyone help me ? thanks a lot!

1. I use DUT and nRF DK module to do the test. When nRF DK module enter tx test and DUT enter rx test, is there a LE connection between them? 2. I have many pair of nRF DK module and DUT work at the same time on the production line, do I need some shielded boxes to ensure them work normally? If two dk modules send one pack at chanel 0,each Dut will receive two packs without shielded boxes? 3. It is mentioned in SDK document as follow:

The purpose of DTM is to test the operation of the radio at the physical level, such as:
•transmission power and receiver sensitivity
•frequency offset and drift
•modulation characteristics
•packet error rate
•intermodulation performance

How can I get the exact frequency offset and drift? do I need a spectrum during DTM? but it is not reality to do that on production line.

Anyone can help? Or which documents should I read? Any tips can be of great help to me! Thank you!

[FormerMember]

The DTM example in the SDK is made in conformance with the DTM specification in Bluetooth Specification Version 4.0, Vol. 6, Part F, and should be fairly easy to use with a Bluetooth tester. The application note nAN34 shows how to set up a production test.

If you don't have a Bluetooth tester, it is easier to do the following for the testing (not production testing):

• Packet error rate (PER): Use the application note nAN34 and its python script to measure the PER.
• The rest of the tests: Connect the output of the radio (after the chip matching network) to a spectrum analyzer and use the radio test example in the SDK (..\examples\peripherals\radio_test). The radio_test example allows you to control the radio PHY over UART.

If using the python script that comes with nAN34, it may be useful to take a look at the DTM Test Setup file in this thread as well.

[Manhull1989]

thank you !