This triggers the transistor and sends the corresponding note to the sound module. By using this method of triggering we overcome quite a few problems that were always associated with contacts. Dirt, dust and humidity are no longer problematic because there is nothing for them to interfere with. Player feel is totally unaffected since there are no springs or wires added to the keys. The natural tone is virtually inaffected and space and weight are kept to a minimum with use of the smallest circuit boards available and the elimination of the mess of wiring that is typical of contact MIDI systems.
Reliability is exceptional since there are no added moving parts to break down.
The MIDI PROFessional is separated into two halves, one each for the Bass and Treble sides. The treble side allows for a maximum of 96 keys and the Bass a maximum of 32. By using combinations of three notes for each chord on the bass side, the full 120 bass mechanics on an accordion can be implemented. The two halves each transmit on separate MIDI channels. The two polyphonic treble channels allow for easier layering and for a split keyboard option on the treble side.