I've been studing a little , and I did something good, for my application.
Just like Fritz said, if my IDB is larger than 4Kb. I can use this
code to find the offset of my FB multi instancied.
But my DB is not larger than that, so Im using that
I know that AR2 have a pointer for the first octet of my IDB, so
for my FB Multi Instancied.
Thanks very much André and Fritz, you guys helped me a lot a understand that,
the pointers, AR1 and AR2 registers.
now i can work very well with Multi-Instances.