Tacx Desktop App (Mac) and Cycelops Hammer?

Hi, I'm trialing the Tacx Desktop training app.  Its the best video of any I've tried, I like it but it doesn't recognize my Cycelops Hammer trainer as a trainer,  just as a Power meter.  So it doesn't control the resistance.  Is this a known issue?  Any way to make it work?  I would really like to subscribe if I can get this to work.

Thanks

Jim