kX UART midi has nothing to do with the DSP or kX router...
But if you want to direct MIDI IN to a kX Synth - you will need; (the DSP and router are now involved because of the kX Synths *audio* output)
- a soundfont loaded in (kX Mixer Soundfont page)
- to use FXBuss 2/3 (kX Synths audio output)
- and theres a MIDI SYNTH slider in the kX Mixer - make sure its not 'INF' (its 100 by default)
- software to connect kX UART MIDI INPUT to *any* MIDI OUTPUT -
midiox - and will act as a sort of virtual MIDI cable while its running. It can also capture/send & load/save your sysex bulk dump too (tho - not a great 'sysex manager').
You can learn a lot about midi with this tool as well.