Yes, the M1KPNAV Navigator keypad can be set to address #1 and used as a primary keypad. Make sure when connecting the data bus from the M1 to the M1KPNAV Data A and Data B did not get reversed (Data A green wire, Data B white wire). Check to make sure you do not have a bad splice connection to the wiring harness. In your Bus configuration you have two home runs — One to the M1XIN’s Daisy Chained and the other to the M1KPNAV? With two home runs the JP3 Jumper on the M1 (above the M1’s RS485 Green Terminal block) should be removed.