Question

28 29 30 6. Examine this trend graph showing a controller's PV and output signals as it controls a loop in automatic mode, and then answer the following questions about the loop based on data evident in the trend: For 6) Please illistate what a P & D output would look like because I dont understand Output why the controller exhibits I only action Time a) b) is the controller direct-acting or reverse-acting? Does the controller exhibit P-only action, l-only action, Pl action, ID action, PD action or full PID action? What value is the setpoint set at in this controller, or is there insufficient data to tell? c)

Answer 1

(a) Reverse acting as output of controller decreases as PV signal Increases CUNOASTERER (4) (c) I - only action set point is 60 For Proportional output contsoller = kp elt) so for as so for r a should be of same stope , just multiplied by output of controlle some constant ° F DES For Derivative controller output a ke delt) .dt so when et is constant, output is zero. only when elts is channing it will give off to ty tit, to tu AUSMRTNOST

WAL CULA SALAN Now here here no action is taken at t, & te where only change due to derivative, as no pv signal is not contant. It appears as opv signal is integrated uz integrator + indirect action due to reverse action

Input to the controller is like step signal and output like inverted ramp signal.

output changes smoothly, no sudden change is there.

Sudden change(step cange) is there in input for proportional controller similar chnage you will observe in controller ouput, which is missing.