Solver Setting  Convergence
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Navigation: User Guide ➔ Menu Commands ➔ View ➔ Solver Settings ➔ Convergence
SS Only  Dynamic Mode Only  

FS_Solver  ProBal  Dynamic  Method  Scenario  Spills  Vents  SS Monitor  SS Finder  Convergence  GlobalTear  Tears  TearTags  Tolerances  Analysis  Changes 
Steady State (ProBal) Parameters
This section describes the parameters on the Convergence tab that are only displayed in a Steady State (ProBal) project.
 The Convergence Tab covers all the information available in the Solver Status window.
 The Convergence Tab offers more indepth information about the solver status than the solver status window.
 The solver status information can be accessed via this tab for reporting purposes.
Tag (Long/Short)  Input / Calc Description  
Convergence...  
Settings (Some of these values can also be entered via Project  Solver Setup)  
MaxIterations / MaxIters  Input  Maximum number of iterations SysCAD will solve for before it stops.  
Iterations  Display  The number of iterations performed in the current run.  
ConvergedItersReqd  Input  The minimum number of consecutive iterations the solved solution will hold for before SysCAD stops.  
ShowErrorColumn  Off  The Error Column in the Solver Convergence Window will be hidden.  
On  The Error Column in the Solver Convergence Window will be displayed, and the Normalised Relative Error will be in fractions (as shown in the picture above ).  
On(Perc)  The Error Column in the Solver Convergence Window will be displayed, and the Normalised Relative Error will be in percent. 
Dynamic Parameters
This section describes the parameters on the Convergence tab that are only displayed in a Dynamic project.
 The Convergence Tab offers indepth information about the solver status.
 The solver status information can be accessed via this tab for reporting purposes.
Tag (Long/Short) 
Input / Calc 
Description  
Convergence...  
Settings  
MaxIterations / MaxIters  Input  Maximum number of iterations SysCAD will solve flowsheet for each step, before it moves on to the next step. (This value can also be entered via Project  Dynamic Setup  Tears) 
Common Parameters
This section describes the parameters on the Convergence tab that are displayed in both Steady State (ProBal) and Dynamic projects.
 The Convergence Tab offers indepth information about the solver status.
 The solver status information can be accessed via this tab for reporting purposes.
Note: Only Type=PipeTear are relevant in Dynamic projects, as these are the only convergence criteria for each step.
Tag (Long/Short)  Input / Calc  Description  
Message.Frequency  Available from Build 139.  
Off  Only available in Dynamic projects. Reporting of tears not being converged is off.  
Continuous  Continuous reporting of tears not being converged.  
StoppedOrPaused  Only available in Steady State projects. Tears not being converged messages will only be reported when model is stopped or paused.  
StoppedOrIdling  Only available in Dynamic projects. Tears not being converged messages will only be reported when model is stopped or idling.  
BadStep.Messages  Tickbox  Available from Build 139. Only visible in Dynamic projects. Report Bad Step (not converged) messages to Messages Log in addition to Conditions window.  
Criteria Counts  
Criteria...  
Type  Count  Active  Busy  Good  Limit  NoFlow  Manual  Off 

PID  Number of criteria  Active or inactive. Eg. If the PID controller is inactive, the PID active value will be lower than the count value 
Busy or not solved. Eg. If the PID controller is not solved, the busy value will be >0 
Good or Solved. Eg. If the PID controller is solved, the Good value will be >0 
criteria values at limit. Eg. If the PID controller output is at limit, the Limit value will be >0 
criteria values with no flow.  criteria in Manual Eg. If the PID controller is placed in manual mode, the manual value will be >0 
criteria Off Eg. If the PID controller is switched off, the PID off value will be will be >0 
FlashTrain  
PipeTear  
Total  
Variable Counts  
Vars...  
Type  Count  Active  Busy  Good  Limit  NoFlow  Manual  Off 
PID  Number of variable, one per criteria  Active or inactive. Eg. If the PID controller is inactive, the PID active value will be lower than the count value 
Busy or not solved. Eg. If the PID controller is not solved, the busy value will be >0 
Good or Solved. Eg. If the PID controller is solved, the Good value will be >0 
variable at limit. Eg. If the PID controller output is at limit, the Limit value will be >0 
criteria values with no flow.  variable in Manual Eg. If the PID controller is placed in manual mode, the manual value will be >0 
variable Off Eg. If the PID controller is switched off, the PID off value will be will be >0 
FlashTrain  
PipeTear  Number of variables, many per criteria  
Total  Total Number of variables  
Maximum variable Errors  
Vars...  
Type  Max  MaxTag  
PID  Maximum PID variable Error  Tag of PID variable with Maximum Normalised Relative Error  
FlashTrain  Maximum Flash Train variable Error  Tag of Flash Train variable with Maximum Normalised Relative Error  
PipeTear  Maximum Tear stream variable Error  Tag of Tear stream variable with Maximum Normalised Relative Error  
Worst  Maximum variable Error  Maximum variable Error Tag  
Solver Convergence  
Converged  Display  Only visible in Steady State projects. A value of 1 indicates that the project is converged (solved), while a value of 0 indicates that it is not yet converged/solved.  
Steps  Display  Only visible in Dynamic projects. The number of steps performed in the current run.  
Steps.Good  Display  Only visible in Dynamic projects. The number of good (converged) steps performed in the current run.  
Steps.Bad  Display  Only visible in Dynamic projects. The number of bad (not converged) steps performed in the current run.  
Iterations  Display  The number of iterations the solver has completed in the current run (overall).  
Iterations.Converged / ConvergedIters  Display  Only visible in Steady State projects. The number of iterations the solver has completed under converged conditions.  
SolveTime  Display  The amount of time taken to solve the project.  
SolveTimeStats  Display  Provides link to the Plant Model  Statistics tab.  
Progress.Error / Prog.Error  Display  Only visible in Steady State projects. This is the Solver progress Bar for errors, when the bar is full, the project is solved. Indicated in the picture above .  
Solver Convergence (Current Step)  
Step.Iterations  Display  Only visible in Dynamic projects. The number of iterations the solver has completed in the current step.  
Step.Converged  Display  Only visible in Dynamic projects. A value of 1 indicates that for the current step, the project is converged (solved), while a value of 0 indicates that it is not yet converged/solved.  
Active  Done  Busy  Progress  
Criteria  Number of Active Criteria Active = Busy + Good + Limit + Manual 
Number of criteria solved Done = Good + Limit + Manual 
Number of Criteria still solving  Criteria solving progress bar, shown in picture above .  
Variables / Vars  Number of Active Variables Active = Busy + Good + Limit + Manual 
Number of Variables solved Done = Good + Limit + Manual 
Number of Variables still solving  Variables solving progress bar, shown in picture above .  
Criteria.GroupByArea  Tickbox  Available from Build 139. If enabled, the following table will be shown with criteria grouped by Area.  
Area  Cvgd  Iters  Active  Done  Busy  Area  
Criteria.AreaX  A value of 1 indicates that the area is converged (solved), while a value of 0 indicates that it is not yet converged/solved.  The number of iterations the solver has completed.  The number of active criteria in the area.  The number of criteria in the area which have been met (solved).  The number of criteria in the area still to be satisfied (still solving).  The name of the area.  
Converge Variables  
CvgNotes...  
No  State  Type  Target  Value  Error  Fails  Area  Tag 
Number: Worst Error Descending Lists up to 20 variables. 
State of the Variable  Type of the Variable  Target value of the variable  Actual value of the variable  Variable normalised relative error  number of iterations variable failed to converge  Available from Build 139. The area the variable belongs to. 
Variable Tag. 
CopyCriteria  Copy To Clipboard Button  Copies selected lists from the Converge Variables table to the clipboard.
Options are:
 
CopyVariables  Copy To Clipboard Button  
Criteria and Variable Counts  
