https://devzone.nordicsemi.com/f/nordic-q-a/111459/differences-bewteen-controlling-the-modem-via-at-commands-and-calling-the-modem-lbraries-apisHello nRF team. Is there any different bewteen passing AT command and directly calling the Modem lbraries APIs(from nRF Connect SDK v2.5.2) to control the modem? For example, changing the modem function mode via +CFUN with Serial LTE modem/AT client applicationen-USTelligent Community 13Fri, 24 May 2024 11:25:41 GMThttps://devzone.nordicsemi.com/thread/485793?ContentTypeID=1Fri, 24 May 2024 11:25:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:fab3269a-eebc-4926-91f7-ac375b766e43Sigurd<p>Hi!</p> [quote user=""]Is there any&nbsp;different bewteen passing AT command and directly calling the Modem lbraries APIs(from nRF Connect SDK v2.5.2) to control the modem?<br /> For example, changing the modem <span>function mode via <span style="background-color:rgba(128, 128, 128, 1);color:rgba(255, 255, 255, 1);">+CFUN</span>&nbsp;with Serial LTE modem/AT client application and calling APIs&nbsp;<span style="background-color:rgba(128, 128, 128, 1);color:rgba(255, 255, 255, 1);">lte_lc_func_mode_set</span><span style="color:rgba(0, 0, 0, 1);">. <br />How are&nbsp;the APIs implemented to control the modem?<br />Is the&nbsp;behaviour consistent between two approach?</span></span>[/quote] <p>Yes, it&#39;s similar.&nbsp;In the case of&nbsp;<span>lte_lc_func_mode_set, and other similar functions, it uses&nbsp;nrf_modem_at_printf() to send the AT-command. You can read about it here:&nbsp;<a href="https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrfxlib/nrf_modem/doc/at_interface.html#sending-at-commands">https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrfxlib/nrf_modem/doc/at_interface.html#sending-at-commands</a></span></p> <p><span></span></p><div style="clear:both;"></div>