https://devzone.nordicsemi.com/f/nordic-q-a/11767/how-to-determine-if-central-fails-to-connect-to-peripheralI am using a central S130 softdevice in an nRF51822. I connect to a peripheral using sd_ble_gap_connect(&amp;m_peripheral_address, &amp;m_scan_param, &amp;m_connection_param) . If it is able to establish a connection to the peripheral, everything proceeds as expecteden-USTelligent Community 13Sun, 07 Feb 2016 00:00:08 GMThttps://devzone.nordicsemi.com/thread/44496?ContentTypeID=1Sun, 07 Feb 2016 00:00:08 GMT137ad170-7792-4731-bb38-c0d22fbe4515:17c792dd-f11d-4a4f-8454-69e28502cd55RK<p>Yes set the timeout parameter in the <code>p_scan_params</code> of the <code>sd_ble_gap_connect()</code> call to something other than zero, which means try forever. <code>p_conn_params</code> are the parameters to use for the connection when connected, it&#39;s the scan parameters which determine how long to search for the peripheral before connecting and when to time that process out and return error</p> <p>This is in the Message Sequence Chart for <code>GAP Central Connection Establishment And Cancellation</code></p><div style="clear:both;"></div>