Solver Setting - Convergence

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	SS Only	Dynamic Mode Only
FS_Solver	ProBal	Dynamic	Method	Scenario	Spills	Vents	SS Monitor	SS Finder	Convergence	GlobalTear	Tears	TearTags	Tolerances	Analysis	Changes

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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 in-depth information about the solver status than the solver status window.
• The solver status information can be accessed via this tab for reporting purposes.

Example Solver Status window:

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 in-depth 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 in-depth 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: State Type Error Descending Fails Descending Tag Block
CopyVariables	Copy To Clipboard Button
Criteria and Variable Counts
Done = Good + Limit + Manual Active = Busy + Good + Limit + Manual Count = Active + Off