PG 2000 Simulator

Dear Experts
I have machine with s5 plc.
The Program is written in STL.
I can open S5 stl program in PG2000 v5.16.
Can i know good simulator for this PG2000.
Also I am upgrading to S7 300 but i am facing regarding program debugging.Can i know best way to upgrade from s5 to s7.

Thank you

https://w3.siemens.com/automation/jp/Documents/5_SIMATIC_S5_S7_renewal_manual_en.pdf

The above is a White Paper on SIMATIC S5 to S7 Migration.

Here is the manual for the PG2000 Software. It mentions the simulator but I have not used it. It is the only one that I know of for the S5.
http://www.process-informatik.de/produkte/data/getText.php?text=61&ART=1&lang=en_

Hope this helps you out.
Regards,

thanks dear