Modicon PL7 PID control question

[Sake_no_oni]

Dear All,

I’m configuring a PID control using Modicon PL7. I have never worked with the Schneider Electric equipment before. Does anybody have any experience with them? Could you please explain me how to program a PID function?
The syntax looks like this

PID(TAG,UNIT,PV,OUT,AUTO,PARA)

1)The PV argument is “Input indicating the measurement for thefunction” (according to the manual). What does “the measurement for the function” mean?

2)What does the AUTO argument does?

3)The main question: the PARA argument determines the set point, proportional gain, integral time, etc. How can I set all of these parameters with only one variable?

Thanks in advance!