You can set an uplink VCP on a standalone switch. You must set an uplink port on the standalone switch as a VCP prior to
Juniper Ex4200 Physical Interconnects
. EX4200 switches are available in models with 24 or 48 ports and with either all, or only 8 ports equipped for PoE. All EX4200
Juniper EX 4500 – Virtual Chassis & Interconnect
EX4500 switches ship with either the intraconnect module or the Virtual Chassis module preinstalled. Both modules are installed horizontally on the rear of chassis.