Solver Setting - Integration

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Navigation: User Guide ➔ Menu Commands ➔ View ➔ Solver Settings ➔ Integration


This page is for Build 138 or earlier. For Build 139 or later, please see Solver Setting - Method.

Tag (Long/Short)

Input / Calc

Description

Dynamic Solver Settings
RealTime.On Tickbox SysCAD will solve the model at a speed relative to the time on your PC. If the RealTimeMultiplier is set to 1 (100%), then it will take 1 second of running time to simulate 1 second of real time.
RealTime.Multiplier Input Multiplier of time when using the RealTime option. If the RealTimeMulitplier is set to 2 (200%), then it will take 1 second of running time to simulate 2 seconds of real time.
StepSize Input The size (time) of each step. A higher value results in a faster relative speed, but generally a less accurate solution. The maximum step size that can be used is dependent on the dynamics of process (relative flow rates, volumes of units, timing of events, etc). A single step can have multiple iterations to solve the flowsheet and associated controls, similar to solving a steady state project. The maximum number of iterations per step is set on the Tears tab .
StepsPerUpdate Input Determines how many steps will be solved before the number displays in trend windows and so on are updated (or stored in historian). Generally the number of Steps per Update is set to 1 so that the number displays are updated at the end of each step.
Integration
Method Input The method used for the dynamic simulation can be changed here.
  • Euler
  • Runge-Kutta 2
  • Runge-Kutta 4
TimeInc.Control Input/Display Only the Fixed option can be selected.
TimeInc.Max Input/Display Maximum step size.
TimeInc.Min Input/Display Minimum step size.
Mag.RelTol Input/Display Relative tolerance. Can only be changed with the Runge-Kutta 4 method.
Mag.AbsTol Input/Display Absolute tolerance. Can only be changed with the Runge-Kutta 4 method.
IntSafety Input
 
DerivEstInc Input
SettleTime Input
 
GrowLimit Input
Grow Input
OKShrinkLimit Input
OKShrink Input
BADShrink Input