Midi Through Question

Hello, I'm trying to do the following set up but can't manage to make it work and I'm starting to think It cant' work. I'm working with a Keytar that has a USB Midi Jack connected to the EXT Device into de Fantom-0. So far it works fine, the Fantom-0 receives the midi wireless without problem. Then I want to transmit that same MIDI messages to the MIDI OUT 5 PIN connector but It doesn't work. I've turned on the MIDI Through in the System Options but I think the midi connectors work independently, I mean I think you can either use MIDI Through using only the 5PIN IN-OUT connector or using only the EXT/ToComputer USB Jacks. Dones anybody know if you can receive MIDI in the EXT-Device and send it through the MIDI OUT 5 Pin output?