a$)$ What can be said about this control loop?

b$)$ Provide the general transfer function of this control loop.

c$)$ Calculate the optimum controller parameters for the best control performance in this control loop.

$]=2\frac{}{}($ dak $)$;$Kc=Kc\frac{u}{2\mathrm{.}2}$;${}_{\text{I}}=[\frac{P_U}{1\mathrm{.}2}$

d$)$ With the optimum controller parameters calculated, does the control variable fit into the set value for a step change of $30$ units in $D?$