Determine BER with nRF Connect Desktop DTM

[bds]

How can I determine BER with nRF Connect Desktop DTM for certification testing?

[ketiljo]

You need to use two instances of the DTM  application that controls two radios. For instance a DK for the transmitter and the device under test, DUT, as the receiver. Setup the transmit time so that it will transmit ~1500 packets. The time depends on the datarate and packet length. Select the same channel and packet type in both instances. Make sure the timeout of the receiver isn't too short. 

Start the receiver, then the transmitter and see how many packet the receiver is counting. The ratio will be the PER.

Also take look at this: https://infocenter.nordicsemi.com/topic/struct_appnotes/struct/appnotes_nan34.html

[bds]

How do I calculate the transmit time from the data rate and packet length? I could not find that in the application note.

[ketiljo]

The easiest is to just try and see how many packet that gets sent in a given time, and adjust as needed.

[bds]

Ok, and where do I see how many packets have been sent? I only found the number of packets received in the UI for the receiver, but not the number of packets sent by the transmitter...

[ketiljo]

If have a good link, e.g, short distance and no strong disturbance, you will have no or close to no packet loss so you can count at the receiver end.