https://devzone.nordicsemi.com/f/nordic-q-a/39884/dtm-firmware-possible-bugHello, I&#39;m checking the DTM code from nRF5 SDK15.2.0. In the ble_dtm.c file, line 763: And in the ble_dtm.h file lines 104-110: DTM_PKT_0XFF and DTM_PKT_VENDORSPECIFIC have the same value. In my opinion if the command being sent is LE_TRANSMITTER_TESTen-USTelligent Community 13Mon, 29 Oct 2018 10:20:30 GMThttps://devzone.nordicsemi.com/thread/154829?ContentTypeID=1Mon, 29 Oct 2018 10:20:30 GMT137ad170-7792-4731-bb38-c0d22fbe4515:757f46a8-6225-4d18-9427-cf6f699bf3e4J&#248;rgen Holmefjord<p>Hi,</p> [quote user=""]In my opinion if the command being sent is LE_TRANSMITTER_TEST then you cannot do a DTM_PKT_0XFF transmitter test as it&#39;s&nbsp;recognized as&nbsp;a vendor specific&nbsp;packet. Is this true?[/quote] <p>Yes, this is true if you are running in 1MBIT or 2MBIT PHY mode. This is also mentioned in the commend (&quot;Bit pattern 11111111 (<strong>Used only for coded PHY</strong>)&quot;). This is intentional, this packet type is only used for BLE Coded PHY.</p> <p>Best regards,<br />Jørgen</p><div style="clear:both;"></div>