Hello.

I'm looking for LFS_External.dll with IS_PLC packet. I search everywere, but no result.. Please help me

There is none.
You can only take the open source and add it yourself if you know how to do it.
I remember I tried once but I got stuck at some point

Yeah, i tried too but no result. Please if another have this LFS_External, i want to share with me

Guys, I wouldn't keep trying to drag LFS External along. It appears to have been abandoned by its creator. InsimDotNet is at least more likely to get updates, and currently will work in the most recent version of LFS with all the functionality.