1. Normally "LP_SCHED" is used to distribute the execution load of the controller on time axis.When the number of controllers increases and there are some ways to distribute load. CPUs with limited number of cyclic interrupt OBs (mainly small S7-300) you need a trick to manage the limited resources.As you have only one PID controller, I don't think it is that crucial to use.But still check the execution time of CPU in online view (in HW.Config) to be in safe side.
   
   
2. Instance DB for each loop contains processing data related to that.Most of the parameters is in your control to be initialized when CPU restart and even to be altered via HMI.It depends on the scenario you want to implement.Configuration tools are provided for temporary adjustment of parameters.You can use samples provided with the product purchased plus Manual of product explaining them in details.

1. I really don't think you need to use loop schedule function if you have only one loop to process.It is hidden in nature of scheduling when you have several things to be done in priorities or orders.But if you still interested in using the function the cycle you select for the function must meet the calling rate of OB3X you are using.For other recommendations , I should see your codes(.pdf version is OK).
   
   
2. The tools provided can be used to manipulate structure of PID controller and be downloaded to PLC.
   
   
3. For changing the value you can use VAT as for sure you have samples to check with addresses of interest.
   
   
4. I am afraid you can not use this package individually to tune your loop.For that you need a new optional package to purchase.As far as I am concerned, I am fearful that package can support your process.For tuning you can use PI controller plus small P and relatively large integration time.If response is not satisfactory, try to change.
   
   
5. Converting Control Parameters from S5 to S7
   
   
6. and my final note is just adhere to safety regulations while working on new ideas.
   
   

1. For enabling complete restart in OB100 and reset the bit,I suggest using "SET" and "CLR" instruction respectively.
   
   
2. Then decide what type of controller you want to choose via selector switches.This is also possible via the configuration tool but you need an initial set up.Initialize the control parameters is also possible here as you have already done in your project.
   
   
3. There are cases may happen in practice that cause a relatively large value as input of PID controller that will lead to a rapid change in LMN.For this option I suggest using rate limiting in output with parameters "LMNRC_ON" ,"LMN_URLM" and "LMN_DRLM". The initial for parameters "LMN_URLM" and "LMN_DRLM" is 10.0 and can be changed via VAT.
   
   
4. About input and output signal I suggest using FC105 and FC106 to avoid complexity of peripheral signals handling in the algorithm.Please, before putting system in auto be sure the proper signals are available to algorithm.Also stroke check the actuator in manual mode.
   
   

Please refer to (Standard PID Control) for more helpful information.

Hope these comments help

Hamid Hosseini