What should you watch out for when calling and assigning parameters to the controller functions in function blocks (S)FB41, (S)FB42 and (S)FB43?
or in the online help of the Simatic Manager.
Hope this helps,
Daniel Chartier

1-First of all we should have information of the process you want to
control and then type of actuator you are using.For general
processes and continuous outputs,using FB41 as integral
part of STEP7 is recommended.You can find plenty of samples
on this function here.For a manual to handle this FB,I suggest
reading (FB41.pdf ).There is also a possibility to see help for
each block in STEP7 by selecting it and press "F1".

2-If you are interested in temperature control, you have option of
using FB58 which is optimized for those processes with integral
tuning facility.More issues are available here:

HD_FB58 Issues
Note FB58 supports both continuous output signal and also binary
output signals.More information is available HERE.
3-For complex control structure you can refer here:

Implementing complex loop configuration with PID controllers

4-For discussion on selecting sampling time of controller refer here:

Selecting an optimum sampling time of PID controllers

5- and finally for tuning option see here:
PID Self-tuner Package


You can specify your application for us to provide all information
you need.