How do I add a new user security code to the system?

To add a user, enter the System or Partition Master code, press [8], enter the 2-digit user number, and then enter the new user's 4-digit security code. The keypad will beep once to confirm the new user was added. The VISTA-20P Series supports up to 47 additional user codes beyond the master code, while the VISTA-15P Series supports up to 31 additional codes. (Page 33)