Rt522 92 -96.docx

RT 522

FLOW CONTROL TRAINER

– Parameterise the controller according to requirements. The parameters below have been determined empirically. The new reference variable with a tolerance band of ±5% (at 350mm approx. 17mm) should be reached as quickly as possible and without overshoot at a reference variable step change of 150mm to 350mm.

RT 512 settings Operating mode

Automatic

Kp (control gain)

5

Tn (reset time)

0,8min

Tv (rate time)

0,0min

w (set point)

Example: Step change from 150 mm to 350 mm

Switch control variable output to current output Tab. 5.5

Settings for the RT 512 controller

RT 522 settings Operating mode

Automatic

Kp (control gain)

0,8

Tn (reset time)

0,14min

Tv (rate time)

0,0min

Dead zone

0,5

Minimum on time (t_min)

0,05s

Tab. 5.6

92Experiments 5

RT 522 controller settings

5 Experiments 1

RT 522

FLOW CONTROL TRAINER

RT 522 settings w (set point)

-

Switch controller to Sxt Tab. 5.6

RT 522 controller settings

All rights reserved, G.U.N.T. Gerätebau, Barsbüttel, Germany 05/2017

– Switch on the pump P1 of RT 512. Now the controller can either be given a manipulating variable in manual mode or a reference variable in automatic mode.

5.4.4

Conducting the experiment – Start the data logger to record the measured values. – In the process control software set the reference variable to w = 150 mm. – Observe the controlled variable of the controlled system and wait until the controlled system reaches a steady state. – Perform the reference variable step change of w = 150mm to w = 350mm. – Observe the controlled variable of the controlled system and wait until the controlled system reaches a steady state. – Stop recording data with the data logger or record the step change back from 350 mm to 150 mm. The trainer must be switched off once the experiments are completed. To do this follow the steps below:

92Experiments 5

5 Experiments 2

RT 522

FLOW CONTROL TRAINER

NOTICE If the controller is not in manual mode and only the pump is switched off, the control valve is opened by the controller until the stop. This means that the next time the control valve is switched on, it is necessary to use the and buttons on the controller to manually move it into a valid operating range.

– Use the buttons on the controller to switch the controller from automatic mode to manual mode. – Switch off the pump. – Disconnect the electrical connection between the two controllers (control variable output y of LICA (RT 512) with the external input wext of FICA (RT 522)) using laboratory cables. – Switch the controller of RT 522 by pressing the "SP-w" button until "SP1" appears in the display. – Press the cascade switch of RT 512 so that the red mark in the switch is no longer visible. – Switch the control variable signal of RT 512 to voltage signal so that the red mark in the switch is no longer visible. The switch is arranged under the sockets for the control variable signal y. – Close the process control software and shut down the PC. – Switch off the main switch on the trainer. – Disconnect the hose connections between the two trainers.

94Experiments 5

5 Experiments 3

RT 522

FLOW CONTROL TRAINER

All rights reserved, G.U.N.T. Gerätebau, Barsbüttel, Germany 05/2017

NOTICE The hose couplings are not self-locking.

94Experiments 5

5 Experiments 4

RT 522

FLOW CONTROL TRAINER

Measured values

Fig. 5.18

Screenshot of a reference variable step change with fill level flow rate cascade control

Tolerance band

5.4.5

96

5 Experiments