I have a problem, I need to connect TC35i with S7-200 and have a possibility to send and recive SMS using it, are there some libraries (free or cheap) to use? or maybe some easy way to control it. Please help! 

Hello nowakian;

Have a look at this discussion. It provides an updated library for the TC35i that you can use for your project. It also suggests you study MAS 5 while using the new library.

https://support.industry.siemens.com/tf/ww/en/posts/mas-5-set-5-and-modem-tc35i/14893/?page=0&pageSize=10

Here is a link to the original MAS 5:

https://support.industry.siemens.com/cs/us/en/view/21063345

Hope this helps, 

Daniel Chartier