https://devzone.nordicsemi.com/f/nordic-q-a/33885/can-i-use-nrf51-dk-to-connect-nrf51822-dut-to-ble-testerHi I am trying to perform BLE compliance test on a nRF51822 based DUT. I want to connect the DUT to the tester using nRF51 DK. The nRF51 DK will be connected to the tester via USB port and to the DUT via UART w/o flow control. The tester would send HCIen-USTelligent Community 13Fri, 04 May 2018 08:54:09 GMThttps://devzone.nordicsemi.com/thread/130962?ContentTypeID=1Fri, 04 May 2018 08:54:09 GMT137ad170-7792-4731-bb38-c0d22fbe4515:7ea8d5ca-e120-478f-a66c-0c5a5dcc8fafketiljo<p>DTM (Direct Test Mode) is the firmware that runs on the device. This accepts commands over two-wire UART as defined in the Bluetooth Core spec. DTM is the standard method to do a Bluetooth compliance test and is used by all BLE testers.&nbsp;</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/130880?ContentTypeID=1Thu, 03 May 2018 18:09:52 GMT137ad170-7792-4731-bb38-c0d22fbe4515:4733752c-9952-46ab-87a8-edc27919dc30Eternauta<p>Hi thank you for your reply.&nbsp;If my DUT has Nordic FW that supports two-wire UART why do I have to use DTM? Thank you.&nbsp;</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/130517?ContentTypeID=1Wed, 02 May 2018 11:52:23 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a0f5fcd9-accf-4639-b4f4-9af73850698aketiljo<p>For BLE testing, you want to use DTM. This doesn&#39;t accept HCI over UART so you must use 2-wire UART instead. See the <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.0.0/ble_sdk_app_dtm_serial.html?cp=4_0_0_4_4">SDK documentation</a>.&nbsp;</p><div style="clear:both;"></div>