40D-Link DIR-865L User Manual
Section 4 - Security
PIN: Select this option  to use PIN method. In  order to use this 
method you must know the wireless client’s 8 digit PIN and click 
Connect.
PBC: Select this option to use PBC (Push Button) method to add a 
wireless client. Click Connect.
Once you click Connect, you will have a 120 second time limit to 
apply the settings to your wireless client(s) and successfully establish 
a connection.