Applies to: Nova, Nova II, SuperNova, SuperNova II, ReMote, ReMOTE SL, SL Mk II, X-Station, K-Station, KS Rack, KS 4/5, D-Station, B-Station rack
The MIDI thru port on any piece of MIDI equipment will output a copy of the signal being fed to the MIDI in port.
So with nothing connected to the MIDI in port, you will not get any output from the MIDI thru port.