Question: what is steady state error in pid controller

title: PID controller
text: PID 0.60 K u ( \ displaystyle 0.60 ( K_ ( u ) ) ) 1.2 K u / T u ( \ displaystyle 1.2 ( K_ ( u ) ) / T_ ( u ) ) 3 K u T u / 40 ( \ displaystyle 3 ( K_ ( u ) ) ( T_ ( u ) ) / 40 )