To fully add an interface to a PAN firewall you can use this command-set – replacing variables as needed.
set network interface {type} {type}{#} layer3 units {type}{#}.{vlan} tag {vlan} interface-management-profile {profile} ip {address}/{mask}
set zone {zone} network layer3 {type}{#}.{vlan}
set network virtual-router {router} interface {type}{#}.{vlan}
set network dhcp interface {type}{#}.{vlan} relay ip enabled yes server [ {dhcp-1} {dhcp-2} ]
set network virtual-router {router} multicast interface-group {m-cast-int} interface {type}{#}.{vlan}
An example (without DHCP-relay or Multicast):
set network interface ethernet ethernet1/1 layer3 units ethernet1/1.500 tag 500 interface-management-profile Allow-Ping ip 10.5.0.254/24
set zone trust network layer3 ethernet1/1.500
set network virtual-router default interface ethernet1/1.500