Ehh, I meant multiple, not several…
Is it possible to use more than one midi controller simultaneousely? E.g. assigning my Korg Legacy Collection MS20 controller to one track/vsti and my Keystation 49e controller to another track/vsti. 
I don’t have two MIDI controllers but I think you can.
ReNoise 1.5’s MIDI config supports two MIDI-in ports
Yes and no…
As It-Alien points out, it’ll accept MIDI-in from two different sources at once (more if you use utilities like MIDI-OX and MIDI Yoke). However, both those will only act on the currently selected instrument at any one time…so you can’t have two different MIDI controllers playing two different Renoise instruments…they’ll both be playing the one you’ve got highlighted at the time.
Not really a workaround (because you still can’t play two different instruments simultaneously), but the numpad + and - buttons might come in handy to move up and down the instrument list quickly if you need access to different instruments in a hurry.
By the way, liking the username. 
Thanx!! I like it too!
And thanx to you both for answering my questions. 
Renoise is the best!!!
you can use midi controllers without selecting the instrument and track if you make use of the midi-cc-device(or vst- if you like).
look for the channel the parameter you want to tweak is sitting at and use Renoise’ internal midi-learn option (called remote mapper i think - where is that in 1.5 btw) to assign it to the controller you want to use. works well, and saves you from having to switch instruments/tracks before you can have a hand on.
You have two MIDI in ports, but you still have 16 channels.
There are a lot of things you can do on those 16 channels, including sending MIDI CC commands, but once all 16 channels are assigned, they are assigned.
If you can use 16 channels across seven midi-devices:then yes, you can control these seven midi devices using the channels. But if you have 16 channels assigned to three MIDI devices and you need 14 more for four other devices, you can’t add any more device unless some of the MIDI devices have special MIDICC commands that can send commands across MIDI segments, but i never heard of MIDI segments and MIDI-switches that can segment MIDI bus-channels 