Help with midi interface for Siel keyboard

I need instructions for using the midi interface with a Siel MK490 keyboard. Is there anyone out there who can help me? I'm desperate!! My manual disappeared long ago.

Is this a special interface designed for the MK? If not, interfaces are usually configured within the computer and once your studio setup is defined it should be just a matter of plug and play.

Everything is set up properly, but it doesn't seem to work. The keys are labeled with functions, one being MIDI. By pressing that key while holding down the "keyboard select" button, it should activate MIDI, but it doesn't seem to do anything. ??