https://devzone.nordicsemi.com/f/nordic-q-a/50403/nrf52840-ble-channel-mapHi All I am right now working with nRf52840DK on Segger Embedded Studio (S140 SoftDevice), and I am trying to read my BLE channel map by function , but I did not get the expected result. Basically, my code is like this: The printf output fromen-USTelligent Community 13Tue, 30 Jul 2019 13:38:57 GMThttps://devzone.nordicsemi.com/thread/201276?ContentTypeID=1Tue, 30 Jul 2019 13:38:57 GMT137ad170-7792-4731-bb38-c0d22fbe4515:517e71ff-8cff-41a7-895d-83f3ac907fe4BOZHENG<p>Hi Andreas</p> <p>Thanks for your reply. Exactly you are right! After connection my channel map printf output becomes default &quot;FF FF FF FF 1F&quot;!!!</p> <p></p> <p><a href="https://devzone.nordicsemi.com/f/nordic-q-a/10520/how-to-correctly-set-channel-map-of-next-connection"></a></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/201227?ContentTypeID=1Tue, 30 Jul 2019 11:53:16 GMT137ad170-7792-4731-bb38-c0d22fbe4515:79680e23-7e41-4f06-ba03-134f4bc9812cAndreasF<p>Hi.</p> <p>Are you connected to a device when you try to run sd_ble_opt_get()?</p> <p>Best regards,</p> <p>Andreas</p><div style="clear:both;"></div>