# Main: APM.IMODE - APMonitor Option

 Type: Integer, Input
Default Value: 3
Description: Model solution mode
1=ss, Simulation (steady state)
2=mpu, Model parameter update (steady state)
3=rto, Real time optimization (steady state)
4=sim, Dynamic simulation (simultaneous)
5=est, Dynamic estimation (simultaneous)
6=ctl, Dynamic control (simultaneous)
7=sqs, Dynamic simulation (sequential)
8=sqe, Dynamic estimation (sequential)
9=sqo, Dynamic control (sequential)


IMODE sets the mode or type of model solution. IMODE=1-3 uses steady state models, meaning that all differential variables are set to zero and there are no model dynamics. Options 4-9 calculate the dynamics with either simulation, estimation, or control. There are three modes each for steady state (IMODE=1-3), simultaneous method to compute the dynamics (IMODE=4-6), and sequential method to compute the dynamics (IMODE=7-9). The first option in each set is simulation (IMODE=1, 4, and 7) where the problem must have the same number of variables and equations and optimization is not allowed. The second option in each set is estimation where model parameters such as FVs and MVs or initial conditions are adjusted to match measured values (IMODE=2, 5, and 8). The third option in each set is optimization or control where controlled variables are driven to a desired target value or an objective function is either maximized or minimized (IMODE=3, 6, 9).