ICAS-PAT manual for Design of process monitoring and ... - CAPEC

3.8.3.1. Click on the command button, “Select the control parameters” and select the
controller parameters from the drop-down list. A message box, asking whether
the user wants to select the default value of the controller parameters will
appear, on selection of controller parameters. The value of controller parameters
will be assigned automatically, if the user will accept the default option.
Otherwise the user needs to type the value of the controller parameters in the
provided text box. Note that only a PI & on-off controller is implemented at this
moment, so the derivative controller constant K D is always set equal to zero. For
on-off controller K switch =0 means open loop and K switch =1 means closed loop.
3.8.3.2. Click on the command button, “Activate the loop”. Similarly the command
button “Deactivate the loop” can be used to deactivate the unwanted control
loop.
3.8.3.3. Repeat the above steps 3.8.2-3.8.3 for all control loops (as a rule of thumb, the
number of control loops should be equal to the number of critical process
variables).
3.8.4. Click on the command button, “Solve the closed loop model”.
3.8.5. Click on the command button, “Load simulation result”.
3.8.6. Click on the command button, “Select variable” and select a critical process
variable that you want to plot. Also select the corresponding set point and
actuator.
3.8.7. Click on the command button, “Operational limit of selected variable”. This
command will provide the lower and upper limit of the critical process variable
(note that the user can modify this limit). The user can also specify the limit of the
actuator in the cells allocated for that information.
3.8.8. To see the result, click on the command button, “Plot”. The closed loop response
of two variables (dissolved oxygen and pH) are shown in Figure 18 as an
example. Actuator plots are not shown.
3.8.9. To analyze the variable, click on the command button, “Analyze the selected
variable” and follow the instructions. If the set point of the controlled variable is
achieved and the actuator is within the limit, then this control variable-actuator
pair can be selected for the final design. As shown in Figure 18 dissolved oxygen
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