Interval Timers

Here it is: I m creating a program for drying dough on S300 PLC.

I have a old program for drying coffee on S200 writen in MicroWin. In that program i find a block called BGN_ITIME and block called CAL_ITIME but i don t understand them.

How can i use those timer on S300 programed via TIA Potral v11 sp2.

If I cant use those timers how can I create a block or function to do same thing as BGN and CAL functions.

Thanks for your understanding, and sorry for my bad english.

I look forward to your replies and help.