tachometer signal for the Vrod

[vbbrown]

Does this signal generate from the crankshaft position sensor, and how does it work? My MC2 heads up display has to tap into this circuit to display RPM, all else works OK but I need some info on this to make a dicision as to tapping into the red wire of the ECU going to the Crank shaft position sensor.
Vbbrown

[V-ROD 1 FL]

PIN 3 on the speedo connector "works for me". The electric manual doesn't say what it is but it does work for this function REAL WELL!!!