Modifying Parameters During a Simulation

Twin Builder lets you pause an in-progress transient or AC simulation, modify the values of unconnectedrealinput properties, then resume the simulation using the new values. Modified parameter values affect only the current simulation run. Corresponding parameter (property) values in the project are not modified.

To modify simulation and model parameters while a transient or AC simulation is running:

1. Right-click the Progress bar and select Change quantity values. You can also click the Progress bar arrow to access the menu.

   Twin Builder pauses the simulator and opens the Set Assignments dialog box. The main panel displays a simulator tree containing a Solution parameters folder, a Solution options folder, a Design variables folder, and icons for each model instance used in the simulation. It may also contain a Project Variables folder if project variables exist in the project.

   Click + next to an item in the tree to expand the item to show its parameters for which new values can be set. Click – to collapse the item. You can also use the keyboard’s right-arrow and left-arrow keys to expand and collapse items in the tree. Similarly, you can use the up-arrow and down-arrow keys to move up and down the tree to select items and parameters.

2. Select the parameter you want to modify.

   The parameter name you selected appears directly below the tree panel along with a text entry field showing the current value for the selected parameter.

   Note:

   Parameter changes made in the Set Assignments dialog box will affect only the Twin Builder circuit and not the external model when performing transient cosimulation with other products such as Maxwell, Simulink, or Ansys RBD.

   1. You can modify the following parameters in the Solution parameters folder:
      • For Transient analyses – Tend, Hmin, and Hmax.
      • For AC analyses – StartFrequency, StopFrequency, and NumberOfSteps.

      For additional information on these parameters, see Transient Analysis Setup and AC Analysis Setup.

   2. You can modify the following parameters in the Solution options folder:
      Note:

      Parameters in the Solution options folder are listed using their netlist names. Each of these parameters corresponds to a setting found in the Solution Options dialog box. The following tables give the parameter name, the corresponding Solution Options dialog box setting name, and the range of values that can be entered for the parameter.

      Transient solution options:

      
      

      Solution options parameter name (netlist name)	Solution Options dialog box name	Acceptable Values
      ADSync	Analog/Digital synchronization	0=Hybrid (default) 1=Adaptive 2=Conservative
      EqualSteps	Number of equal steps	positive integers
      IEmax	Maximum current error	positive real values >0
      Iteratmax	Maximum number of iterations	positive integers >=1
      LDF	Local truncation error [%]	positive real values >0
      PerformanceFactor	Simulator pivoting strategy	positive real values >=0, <=1 (0=Partial, 1=Complete)
      RelTol	Relative tolerance [%]	positive real values >0
      SamanskiiFactor	Samanskii factor	positive integers >= 1, <=100
      Solver	Integration formula	0=Euler 1=Adaptive Trapezoid-Euler(default) 3=Trapezoid
      StepAccelDamping	Step acceleration damping [%]	positive real values >0
      Temp	Ambient temperature (Cel)	real values >0
      VEmax	Maximum voltage error	positive real values >0

      
      

      AC solution options:

      
      

      Solution options parameter name (Netlist name)	Solution Options Dialog Name	Acceptable Values
      EmaxAC	Maximum error [A]	real values >0
      Iteratmax	Maximum number of iterations	positive integers >=1
      Temp	Ambient temperature (Cel)	real values >0

      
      
   3. You can modify properties for design and project variables, and for component properties as defined in their respective Properties dialog boxes.
   4. Enter the new value for the selected parameter in the text field and click Set to send the new value to the simulation engine.

   The Assignments panel echoes the newly assigned values. Modify the parameter values listed in the Assignments panel. Reselect the parameter in the tree, enter the desired value, and click Set to update the listing.

3. Repeat steps 2 and 3 for any additional values you want to modify.
4. When finished, click Continue to close the Set Assignments dialog box. The simulation run resumes using the modified values.