I am using the most recent version of RNG Reporter and I am trying to teach myself RNG for Leaf Green (off of the cart).
My problem right now is that I am not certain how to locate the PID of a caught Pokemon for calibration purposes (I plan on using Omega Donuts process here: http://www.smogon.com/forums/threads/rng-manipulation-in-firered-leafgreen-wild-pokémon-supported-in-rng-reporter-9-93.62357/page-17#post-4018452)
So I get Abra (or any other Pokemon for that matter) and then what? I've found the exact IVs for Pokemon but have not been able to find the seed even when using the correct generation method.
If I were you, I wouldn't even bother trying to RNG off the cart in FR/LG. It's just too unpredictable/unreliable.
To answer your question, though, there's a "Calculate PID from IVs" feature in RNG Reporter (should be in the 4th gen tools tab, but it works just fine for 3rd gen as well).