< Mentor Note -- thread moved to HH from the technical forums, so no HH Template is shown > Hi! I am trying to reduce a PID controller by using block reduction rules but I am having some trouble Here is the block: https://postimg.org/image/9am5n8bsp/ My attempt: 1. Multiply (1/I)*(1/s) -> (1/Is) 2. Reduce this with Kd. Since they are parallel, I reduced it to: (1/Is)/(1+Kd*(1/s)) and it is now I'm lost. What do I do with the K (should I even use this one?) on the left side and the 1/s that is on the right side? Should I multiply these two with (1/Is)/(1+Kd*(1/s)) since they are in series with each other? Would appreciate if someone could explain this last part. One hint is that the input signal (source) and the output signals not are included in the transfer function. Thanks!