thanks for the pdf it appears to be a recofiguration of the classic block diagram
error_in >> controller >> system >> process
^^^^ <<<<<<<<<<<<<<<<<<<vvvvv
from what I can tell the document is saying to use the actuator value as
the input from 0 to 100 percent……..and either the process or the input error in the PIDtuner column labelled output
this clarifies that the error is not the input but now I am back to clarifying the output column , as to be needing the
since the document kind of goes in circles Im still seeking to clarify if that is the system or the error that will work best for this (in the output column data)