# Main: Simulation

## Dynamic Simulation

The DBS file parameter imode is used to control the simulation mode. This option is set to 4 (simultaneous simulation) or 7 (sequential simulation) for dynamic simulation.

 apm.imode = 4 (simultaneous dynamic simulation)
apm.imode = 7 (sequential dynamic simulation)

% MATLAB example
apm_option(server,app,'apm.imode',7);

# Python example
apm_option(server,app,'apm.imode',4)


Like steady-state simulation, dynamic simulation requires a square problem with no degrees of freedom (neqn=nvar). Dynamic simulation has many useful purposes including

• Investigate step response characteristics of a nonlinear model
• Simulate process changes for design, trouble-shooting, or planning
• Perform what-if scenarios
• Simulate a virtual process

Dynamic simulation is the easiest dynamic mode to configure and run. The requirement for a square problem facilitates model convergence as the solver has only to achieve feasibility with the equality constraints.