https://devzone.nordicsemi.com/f/nordic-q-a/119829/esb-ptx-and-prx-with-ack---how-long-is-the-ack-from-prxHi, we have ESB PTX and PRX couple from nRF54H20 nRF54H20DK (rev. 0.9.1), SDK: v2.9.0-nRF54H20-rc2 and the same Toolchain, IDE: VSCode + nRF Connect plugin build for CPURAD configured to 4Mbps ~ 2us/byte ACK and never disable TX radio I need transmiten-USTelligent Community 13Tue, 18 Mar 2025 08:56:23 GMThttps://devzone.nordicsemi.com/thread/527782?ContentTypeID=1Tue, 18 Mar 2025 08:56:23 GMT137ad170-7792-4731-bb38-c0d22fbe4515:cbd195db-1766-4db7-83d9-6123f3d58fecHung Bui<p>Hi Peter,&nbsp;<br />If you don&#39;t switch between TX and RX (to receive ACK) then you don&#39;t need ESB_FAST_SWITCHING. If you do need ACK then you shouldn&#39;t turn&nbsp;<span>ESB_NEVER_DISABLE_TX&nbsp;=y.&nbsp;</span></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/527710?ContentTypeID=1Mon, 17 Mar 2025 15:55:37 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5ee2b781-a8eb-439f-b40d-aa399851bcdfPeter Langer Keysoft<p><span>Activating ESB_NEVER_DISABLE_TX is excluded from the activated ESB_FAST_SWITCHING.</span></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/527695?ContentTypeID=1Mon, 17 Mar 2025 15:05:22 GMT137ad170-7792-4731-bb38-c0d22fbe4515:aeb99ffa-1c4b-4766-80ef-d37aa9eac7abHung Bui<p>Hi Peter,&nbsp;<br />Could you double check if you have&nbsp;<a href="https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/protocols/esb/index.html#fast_ramp-up">CONFIG_ESB_FAST_SWITCHING</a>=y&nbsp; in your .config output file ? if not please add to the prj.conf. It should be able to reduce the time switching between TX and RX. You need that on the PRX as well.&nbsp;<br /><br /></p><div style="clear:both;"></div>