Hi Glen,
Actually F6 and Dm7 are same chords as they sound the same just like say, C6 and Am7 because they use the same notes. Any major sixth chord has it's correspondant minor seventh. This is one particular thing about chords.
Here's another one...
Cdim = Ebdim = F#dim = Adim using C Eb F# and A notes and their inversions.
Inversions are quite useful when playing left handed chords so can you make the less possible movements with your fingers. Many times you only have to change one or two fingers to go from one chord to another. You'll have to experience by yourself and the KN7000 can help you a lot by showing on the screen the name of the chord your're playing.
Hope this help
Serge