how can I connect midi the bitbox 2 with multi-io

[XORadmin]

how can I connect the bit box 2 via midi?

A Midi cable. Maybe either just a stereo minijack cable if the Bitbox does use the Midi standard TRS-A anf if not then you need a TRSA-B Adapter or you use regular Midi cables together with the adapters which are delivered with the Multi-IO. Or I guess via USB?

Is it possible with the matrix to give the trigger and the keynote?

There is in reality no such thing as a trigger in Midi. There is only Note On and Off. And different types, Note on only, Note on following Note off directly or Note on followed by a note off on another step is one of the drummatrix features indeed.

Hi Thomas 
so I can use midi pattern but not drummatrix in midi?
does the midi patern only have 4 viewable channels?

I think you didn't understand what I wrote but yes you can use midi in the drummatrix.

Also I think that it is quite a luxury thing to have 4 midi columns per track in a midi track. Nearly all eurorack sequencers out there got only 1 possible midi note per track. And in the drummatrix you can have 16 midi notes per track which is not too bad either I would way (if I compare again with other sequencers which I never do normally, but it gives you a clue that 'only 4 viewable channels' is quite cool  ).

Page 110 of the V2.01 manual gives you some information about the assignment. In V2.02 there is an additional Midi trigger mode (On/Off) and you might end up using that depending on how the bitbox works.