Topic: Alphatrack and MaxMSP

Hi, I'm new here and I can't speak UK very well.
I've own a Alphatrack and I'm trying to communicate via Sysex with a patch in MaxMSP

Now I've read the Midi Sysex specs in the Alpha-Track Native 1.0 pdf tutorial.
To become a Led active on the panel of the AlphaTrack I'm trying to send him the string "90 46 7f"...that's for the Shift Led, and the string in MaxMSP results as 240 90 46 7f 247 (240 is 0xF0 and 247 is 0xF7)

But nothing happens

Where is my error? Should I prepend to every string the Frontier Design Group manufacturer’s system exclusive ID ("00 01 40”) and the the AlphaTrack ID ("20 00 01 00”) ? That gives a extremely long string at every programming strip....

Note: the Alphatrack is just in Native mode, and the Midi ports in MaxMSP are set correctly.

Best regards
Italo