Convert S5 program into TIA V12 program

Hii Experts,

I had convert S5 program into S12 TIA program.

As in S5 program in some ladder they had used STL language but S12 does not support STL , so i had manually translated it into LAD language.

But there was some block like,

FB201

FB204

FB210

FB211

FB212

FB213

FB225

FB226

FB240

FB241

FB242

FB243

FB250

FB251

SB 2 which is in STL language and i am not able translate this STL program in LAD program as i am new in Siemens.

I think this is system internal block.

So my question is that is it compulsory use this block in S12 program??

Can any one help me plz.

Thanks in advanced.

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Split from S5 to S7 Conversion.