Contents

Introduction to Powersim Run-Time

User Environment

Getting Started

Menu Commands

Presenting Simulation Results

Terminology


Introduction to Powersim Run-Time

Welcome to Powersim Run-Time, a special variant of the Powersim simulation software that allows you to run ready-made simulators. Some key characteristics are described below.

Main Run-Time Features

Powersim Run-Time Capabilities

Comparison of Run-Time and the Full Development Package

System Requirements


Main Run-Time Features

Low-Cost Alternative for Model Users

Powersim Run-Time is offered as a low-cost alternative for model users who do not need the full-scale modeling capabilities of the authoring version of Powersim. The user of a simulation model is not always directly involved in the modeling process. While managers, decision-makers, politicians, students, or other users may participate in discussions leading to the creation of a model, the programming of the model as a simulator is performed by those with special modeling skills. In such cases, many people may wish to perform simulation experiments on models created by others.

Simplified User Interface

Menus and toolbars in Powersim Run-Time differ from the full Powersim software package to allow you to concentrate on the particular simulator or model.


Powersim Run-Time Capabilities

•	Open runnable Powersim documents and their accompanying Help files

•	Perform simulation runs

•	Adjust model parameters using input presentations

•	Inspect variable scaling and simulation setup

•	Save documents with simulation results

•	Copy simulation results to other programs

Note	Powersim Run-Time may not be used to create new documents, open documents containing not-runnable models, perform editing or formatting actions on existing documents, or change variable scaling and simulation setup. For these purposes the full Powersim package is required.


Comparison of Run-Time and the Full Development Package
Comparison of Run-Time and the full Powersim package

Functionality	Powersim	Powersim Run-Time
Startup with "empty" document	A (Available)	N/A (Not Available)
Toolbar	A	N/A
Format, Color, and Tools menus	A	N/A
Commandbar buttons: New, Undo, Cut, Paste, Straighten, Rotate Name, Move Valve, Options	A	N/A
File menu items: New, Save All	A	N/A
Edit menu items: Undo, Cut, Paste, Select All, Clear, Reverse Flow, Define Object, Define Range, Define Unit	A	N/A
View menu items: Diagram, Equations, Toolbar, Show What, Pages, Rulers	A	N/A
Window menu items: New Window	A	N/A
File Properties: Change contents in text boxes and open Access dialog box	A	N/A
Edit Scale: Change settings	A	N/A
Simulate Simulation Setup: Change settings	A	N/A


System Requirements

The following equipment is required to run Powersim Run-Time:

•	IBM compatible PC with 80386 processor or greater

•	Windows 3.1x, Windows NT, or Windows 95

•	4-8 Mb RAM or more

•	Hard Disk with 10-20 Mb free space

•	Mouse


User Environment

Powersim Run-Time's application window displays the menus and provides the workspace for any simulator run by the application.


Menubar

The menubar is located below the title bar at the top of the application window and contains all the Powersim commands. To view all the commands in a menu, do one of the following:

Click the menu name

Press Alt + N , where N is the underlined letter in the menu name

For example, press Alt + F to open the File menu.

Menu_Commands>main  for a detailed description of each entry in the various submenus.


Commandbar

The commandbar is located below the menubar, and contains a set of buttons for performing the most frequently used commands in Powersim Run-Time.

Open	Save	Copy	Zoom out	Zoom in	Zoom to 100%	Zoom to fit in window	Run	Run Step	Pause on/off	Stop


Workspace

The workspace is where you view causal loop and flow diagram models and adjust model parameters using input presentations.


Statusbar

If visible, the statusbar is displayed at the bottom of the Powersim application window. It contains different kinds of status information, for example, context-sensitive menu help and the current simulation time.


Getting Started

This topic contains step-by-step instructions of how to perform an experimental simulation session using Powersim Run-Time. By following these instructions, you will learn how to open and simulate a ready-made Powersim model.

Opening a Ready-Made Model

Performing a Base Run

Adjusting Parameters

Testing the effect of a parameter adjustment


Opening a Ready-Made Model

1	From the File menu of Powersim Run-Time choose Open or click Open [image] in the commandbar.

2	From the Open dialog box select the document WORLD5.SIM (this is a demo document provided with your Powersim Run-Time software) from the File Name listbox and hit OK.


Performing a Base Run

1	Choose "World Dynamics - Time Graph" from the Window menu.

2	Click Run [image] in the commandbar to start a simulation run based on the original parameter values of the model.

As the simulation runs, you will see that the current simulation time is indicated in the statusbar. This particular model runs from the years 1900 to 2100 a.d. The time graph in which the simulation results are displayed shows the development of the variables QL, POLR, CI, P, and NR. These are key variables in this model.

3	Now look at the time graph, the legend at the right-hand side of the graph identifies the time-series curves of the diagram and it also indicates how the variables are scaled on the y-axis.

For example, the time-series of the variable QL (Quality of Life) is labeled "1" in the diagram, and its min and max values are 0 and 2 respectively. In this run, the variable QL starts at a value of about 0.5 in year 1900, rises steeply to 1 around year 1950, then declines rapidly to 0.6 around year 2020, and finally declines in an S-shaped manner to 0.5 in year 2100.


Adjusting Parameters

To simulate the impacts that different actions might have on the global system, we can make parameter adjustments before or during a simulation run. Suppose we assume that in the year 2000 the usage rate of natural resources is sharply curtailed without affecting any other part of the system. This might correspond to a natural decline in the actual rate of consumption relative to the available stocks in the earth, or it might correspond to advances in technology that allow for decreased use of natural resources.

In WORLD5.SIM, the "Parameters" window allows you to adjust this and other parameters by moving the slider button or clicking the number box of the desired parameter.


To test the effect of a parameter adjustment
Testing the effect of a parameter adjustment

After opening WORLD5.SIM and performing a base run, follow these steps:

1	From the Window menu, choose Parameters. Note that the original value of NRUN is 1.0.

2	Start a new simulation.

3	When time has reached 2000, pause the simulation by hitting Pause [image] in the commandbar.

4	Adjust the parameter NRUN (Natural Resource Usage Rate) to 25% of its original value. You can do this by either dragging the button of the NRUN slider down to approximately 0.25 or by clicking the number box on top of the NRUN slider and then typing 0.25 in the Number dialog box.

5	Resume the simulation (switch pause off) by hitting Pause [image] again.

If you compare the results of this simulation with the first run, you will see an explosive growth in the POLR (Pollution Ratio).


Menu Commands

This topic provides you a detailed description of all commands and options found in Powersim Run-Time's menus. Some of these are also available as buttons in the commandbar.

Overview of menus

File menu  - Open, save, print documents, or quit Powersim

Edit menu - Copy areas, inspect scaling, and search for variables

View menu - Show/hide commandbar and statusbar, zoom diagram

Simulate menu - Set up and inspect simulation runs

Window menu - Rearrange windows or activate specified windows

Help menu - Get help on using Powersim

See also

Choosing a Menu Command


Choosing a Menu Command

 Using the Mouse

1	Point to a menu name

2	To display the menu, click the left mouse button

3	Point to a command name

4	Click on the command name with the left mouse button

 Using the Keyboard

1	To make the menubar active, press the Alt key

2	To display a menu, press the underlined letter in the menu name

3	To choose a command, press the underlined letter in the command name

Hint 	Powersim assigns some commands to shortcut keys so you can choose the commands without displaying a menu. If a command has shortcut keys, the keys appear in the menu next to the command.


File menu

You use this menu to open, save, and print documents, or quit Powersim Run-Time. To use a document, you must first open and display it on your screen. You can then perform simulation runs.

Overview of File menu commands

Open - Opens an existing document

Close - Closes all windows of the active document

Save - Saves changes made to the active document

Save As - Saves and names the active document

Page Setup - Defines page setup for the current document

Print - Prints the active window according to the parameters you specify

Print Setup - Identifies the printer you want to use and sets options for it

Properties - Displays properties of the active document

Exit - Quits Powersim, prompts to save any unsaved documents


Open (File menu)
Open

Use this command to open an existing Powersim Run-Time document.

If you have recently worked on a document, you may be able to open it again by choosing it from the File menu, where Powersim lists the documents you most recently opened.

To quickly open a document, click Open [image] on the commandbar .

Hint	Powersim allows you to work on several opened documents at the same time. Use the Window menu to move between document windows as you work.


Open dialog box (File menu)
Open dialog box

File Name

Type or select the name of the file you want to open. This box lists files with the extension you select in the List Files of Type box. If the document you want to open is not listed in the File Name box, do one or more of the following:

•	In the Drives box, select a new drive.

•	In the Directories box, select a new directory.

•	In the List Files of Type box, select the type of document you want to open with its 3-character extension.

You can also see a list of all files with a specific extension in a drive or directory. In the File Name box, type an asterisk (*) before a period (.) and the extension. For example, to see all the files with a TXT extension in a directory, type «*.TXT» in the File Name box. To see all the files in a directory, type «*.*».

Directories

Select the directory in which the file you want to open is stored.

Drives

Select the drive in which the file you want to open is stored.

List Files of Type

Select the type of file you want to open. Available file types are listed below:

File type	Lists
Powersim Document (*.SIM)	All files in the current directory with a SIM extension
All files (*.*)	All files in the current directory


Protection Password dialog box

Note	When you try to open a file which is protected by a password, the Protection Password dialog box is first opened, and you are asked to enter the password.

Enter password for file ...

Type the password in the text box and hit OK. If you choose Cancel or the password is incorrect, the file is not opened.

To set a new password for the document, hit Password [image] in the Save As dialog box.


Opening an Existing Document on Startup

Powersim Run-Time can be made to automatically open a simulator document on startup, by giving the desired simulator document name as a parameter in the command that starts Powersim Run-Time. In the following command example Powersim will automatically open the document POP.SIM on startup:

C:\POWERSIM\POWERSIM.EXE POP.SIM

To open a document on startup in Windows 3.1x or Windows NT

1	Open the Program Item Properties dialog box from Windows Program Manager

2	Enter the desired simulator document name as a parameter to the Powersim Run-Time exe-file in the Command Line text box.

To open a simulator document on startup in Windows 95

1	Open the Taskbar Properties dialog box by selecting Start, Settings, Taskbar

2	Choose the Start Menu Programs tab from the Taskbar Properties dialog box

3	Click the Add button to open the Create Shortcut wizard

4	Enter the desired simulator document name as a parameter to the Powersim Run-Time exe-file in the Command text box.


Close (File menu)
Close

Use this command to close all windows containing the active document. If the active document has been changed (i.e., if you have performed one or more simulation runs), a dialog box will appear asking if you want to save your work. If you close a document without saving, you lose all changes made since the last time you saved it.


Save (File menu)
Save

To quickly save a document with its existing name, location, click Save [image] on the commandbar.

Note When you open an existing document, Powersim copies it from the disk where it is stored and displays it in one or more document windows. As you work, you are actually making changes to the copy of the document. To keep your latest work safely on the disk, you should frequently save your document. Each time you save a document, it remains open on your screen so you can continue work.


Save As (File menu)
Save As

If you want to save the name or location of an existing document before you save it, choose the Save As command. It can also be used for changing directories.

Save As dialog box

File Name

Type a new filename to save a document with a different name. Use the current name, or select a name in the list to save a document with an existing filename.

A filename can contain up to 8 characters and an extension of up to 3 characters. If no extension is specified, Powersim adds the extension you specify in the Save File As Type box, normally SIM.

Directories

Select the directory in which you want to store your document.

Drives

Select the drive in which you want to store your document.

Save File as Type

Select the file type of the document to be saved. Available file types are listed below:

File type	Save file in format
Powersim Document	Standard Powersim document
Powersim Equations	Text file containing model equations in order of execution.
Password

Opens the Change Protection Password dialog box for specifying password protection of your document.


Change Protection Password dialog box

You can protect a document with a password to prevent others from opening it. If you protect a file with a password, you must provide the password each time you open the document. Use the Change Protection Password dialog box to set a protection password for the document.

Protection Password

Type the new password in the text box. To remove an existing password, leave the text box empty.

Cancel

Closes the dialog box and the original password is retained.

OK

Closes the dialog box and opens the Confirm Protection Password dialog box. If the text box is empty when you press OK, the current password is removed (provided that you confirm the removal in the Confirm Protection Password dialog box).


Confirm Protection Password dialog box

Reenter Protection Password

Type the new password again in the text box. To confirm the removal of a password, leave the text box empty.

Cancel

Cancels the change of the password.

OK

When you hit OK, Powersim checks that you have typed the password in the same way in the Change Protection Password dialog box and the Confirm Protection Password dialog box. If not, a message box appears, saying "The password confirmation does not match", and the Change Protection Password dialog box is presented again.


Page Setup (File menu)
Page Setup

Use this command to change margins, header and footer, and print size.

Page Setup dialog box

Margins

Use this group to specify the margin options listed below.

Top

The margin from the top of the page to the top of the diagram.

Bottom

The margin from the bottom of the page to the bottom of the diagram.

Left

The margin from the left edge of the page to the left of the diagram.

Right

The margin from the right edge of the page to the right of the diagram.

Header / Footer

Headers and footers are descriptive texts that print in the top margin or bottom margin of every page in your document.

In the header or footer text box, you may type the text that you want to appear on each page of your document. Fields may also be inserted; this is done in one of two ways.

•	By pushing Field [image] and selecting among the listed fields in the Field dialog box. (You must first click in either the header or footer box to activate the Field option.)

•	By typing the appropriate field code directly into the Header or Footer text box.

From Edge

Displays the distance between the Header or the Footer and the top or the bottom of the page, respectively. The contents of each of the two text boxes is a number followed by the currently chosen measurement unit.

Note 	The settings should be coordinated with the Margins settings, found in the same dialog box, to prevent the header/footer from falling outside the top/bottom margins.

Print Size

The setting of this list determines the printing size to be used. You may choose among the following sizes: 25%, 50%, 100%, 200%, and Fit to One Page. The latter ensures that Powersim adjusts everything to print on one page.

Note	The printing size affects the page borders and the rulers of the diagram, since both of them are tied to the printer and not to the screen. If the printing size is decreased, the distance between page borders on the screen is increased. Correspondingly, the distance between unit tick marks of the rulers is increased. The zooming percentage of the diagram, however, remains unchanged.

Field

Opens the Field dialog box so you can insert fields in the Header or Footer text box.


Field dialog box

Use the Field dialog box to insert a field code at the text marker of the active text box. Fields are coded instructions that insert textual, numerical, or other information into your document. Which field types that are available depends on the context in which the Field dialog box is opened. Field Types and Instructions  shows the field types available for the various dialog boxes in Powersim.

Insert Field Type

Select the type of field you want to insert. The box lists the fields available for the active text box. Selecting a field from the list replaces the contents of the Field Code text box with the field you selected.

Instructions

Choose any additional instructions for the field type. The box lists the instructions available to the selected field. Select an instruction from the list and hit Add [image] to add the instruction to the Field Code text box.

Field Code

This box shows the field type and instructions you can select or type. You can edit the field code in this text box as well.

Add

Adds the selected instruction to the Field Code text box.


Field Types and Instructions

List of Available Field Types

Field type	Displays	Instruction group (table below)
PAGE COLUMN ROW	Page number Column number Row number	Numbering Formats
FILENAME	File name of document	None
TITLE	Title of document	None
AUTHOR	Author of document	None
TIME	Printing time and date	Time Formats
Field Instruction Groups

Instruction group	Instruction	Description
Time Formats	yy	Year (92)
	yyyy	Year (1992)
	m	Month (1..12)
	mm	Month (01..12)
	mmm	Month (Jan..Dec)
	mmmm	Month (January..December)
	d	Day (1..31)
	dd	Day (01..31)
	ddd	Day (Mon..Sun)
	dddd	Day (Monday..Sunday)
	h	Hour (0..23), (0..11 if AM/PM)
	hh	Hour (00..23), (00..11)
	m	Minute (0..59), Must be after 'h'
	mm	Minute (00..59), Must be after 'h'
	s	Second (0..59)
	ss	Second (00..59)
	AM/PM	Use 12 hour clock
	am/pm	Use 12 hour clock
	A/P	Use 12 hour clock
	a/p	Use 12 hour clock
Numbering Formats	1, 2	Arabic
	I, II	Roman Capital
	i, ii	Roman Versal
	A, B	Letter Capital
	a, b	Letter Versal


Print (File menu)
Print

Use this command to print your documents.

Print dialog box

Printer

Displays the active printer and printer connection. To specify a printer and its connection click on Setup [image].

Print What

The settings here determine the contents of a print-out. Use the list box to select what you want to print (see the table below).

Selection	Result
Diagram	Prints only the diagram. All variables and presentations that are visible in the diagram view will be printed.
Equations	Prints only the equations. The printing corresponds to the information displayed in equation view.
Diagram + Equations	Prints diagram and equations. The diagram is printed first.
Front Page

Check this box to include a front page containing information from the Properties dialog box (title, author, and description).

Empty Pages

Check this box to print empty pages as well as pages with contents.

Print Range

Use this group of options to specify the range of a print-out.

All

Prints the entire document.

Selection

Prints the currently selected part of the diagram.

Window/Area

Prints the current window or diagram area. If no area exists, this option is named Window, meaning that the current window is printed. If an area exists, this option is named Area, meaning that only the contents of that area is printed.

Pages

This option allows you to print specific pages, or ranges of pages, by typing the appropriate numbers in the From and To boxes.

From - To

Specify the number of the first and last page you want to print. Leaving a box blank results in the printing of all remaining pages (or all preceding pages). Examples are shown below:

From	To	Print result
1	1	Page 1
3	-	Page 3 to end of document
2	3	Pages 2 and 3
-	5	Beginning of document to page 5
3	1	Pages 3 to 1 in reverse order
Print Quality

Choose the resolution (typically measured in dots per inch; DPI) at which you want to print graphic images. Open the list and choose the resolution you want to use.

Note 	If diagrams print only partially, the reason may be that your printer does not have enough memory. Reduce the Print Quality (for example, from 300 to 150 DPI) and try printing again.

Copies

Type or select the number of copies you want to print.


Print Setup (File menu)
Print Setup

Use this command to choose printer, orientation, paper size, source, etc.

Print Setup dialog box

Printer

Use this group to choose the printer you want to use. Only printers you have installed will appear.

Default Printer

If selected this option uses the printer established as the default by the Windows printer setup. If you change the system default printer, all documents that were stored with the default printer setting will automatically print on the new printer.

Specific Printer

Select this option to choose a particular target printer from the drop-down list. This choice is stored with the document so that the document will always print on that printer, even if the system default printer is changed.

Orientation

Portrait

In portrait mode, your document will print vertically on the page.

Landscape

In landscape mode, your document will print horizontally on the page.

Note	If one of the modes is not available for the current combination of printer and paper type, the label and option button for that mode are dimmed, and the option button for the available mode is selected.

Paper

Use this group of options to choose the size and source of paper you want to use.

Size

Choose paper size from the drop-down list, which specifies the paper sizes that can be loaded into the printer.

Source

Selects the paper source in the printer.

Options

Displays a dialog box so you can set additional printing options (for example, specify dithering, intensity, etc.) that will be stored with the document. This button is dimmed if no such options are provided by the current printer driver.

Note 	If you have a Hewlett-Packard (HP) compatible printer, you should turn on the option "Print True Type as Graphics". If this option is switched off, text will not print properly.

Note 	If you are using a monochrome screen and a black and white printer, text, lines, borders, and shadows will always print as black.


Properties (File menu)
Properties

Use this command to display key properties of the current document, such as title, author, statistics, and access rights.

Properties dialog box (read-only)

File Name

Displays the filename of the active document.

Directory

Displays the location of the file.

Title

Displays the document title.

Author

Displays the name of the author. Powersim automatically inserts the name you typed when you installed Powersim. You can use a different name by typing it in the Author box.

Description

This field may contain a description of the model you are running. For example, what problem or phenomenon it describes, or what patterns of behavior it depicts.

Statistics

Click on this button to display document statistics, such as, the number of variables in the model. Powersim automatically updates the statistics when you open the Statistics dialog box.


Statistics dialog box

The following table describes the fields of the dialog box.

Field	Displays
File Name	The file name of the current document.
Directory	The directory in which Powersim stores the active document.
Title	The title of the document entered in the Properties dialog box.
Author	The author of the document entered in the Properties dialog box.
Created	The date and time you created the document.
Last Saved	The last date and time the document was saved.
Last Saved By	The name of the person who last saved the document (i.e., the registered user of the Powersim copy used to save the document).
Number of Items	The number of various entities found in the current document.


Exit (File menu)
Exit

Use this command to quit Powersim.


Edit menu

You use this menu to copy areas from your document, view the scaling of variables, and to search for variables in a diagram.

Overview of Edit menu commands

Copy - Copies the selected area and places it on the clipboard

Scale - Displays the min and max scaling settings for variables

Find - Searches for a variable in the active diagram


Copy command (Edit menu)
Copy

Use this command to copy a selected area onto the clipboard. This command is unavailable if no area is selected. Copying something to the clipboard replaces the contents previously stored there.

To quickly copy information to the clipboard, click Copy [image] on the commandbar.


Scale (Edit menu)
Scale

Use this command to activate the Scale dialog box to review scaling options for the variables in your model. A variable is scaled by determining what min and max settings are to be used in the graphical presentations of its simulated values.

Scale dialog box (read-only)

Models

Displays the model which the scaling options apply to. The list contains the main model and all connected co-models.

Update Dynamic Scale on Pause

If this box is checked, the Edit Rescale Now command is automatically performed whenever a simulation is paused. (This option applies to all variables, not only to the selection in the Variables list.)

Variables

Displays the variables and their scaling options. The list contains all variables of the model displayed in the Models list. It has three main columns: Variable, which lists variable names, and Min and Max, which show the variable's current minimum and maximum values.

In addition, the Min and Max columns each have an icon that indicates whether the scaling is dynamic or fixed (see table below).

	Min	Max
Fixed
Dynamic
Dynamic

Dynamic min/max values are automatically updated whenever a simulation run has terminated. For example, when you choose Simulate Stop or when the simulation time reaches the stop time, as defined in the Simulation Setup dialog box.

If the Update Dynamic Scale on Pause box is checked, the dynamic scaling is also updated whenever a simulation is paused, such as when you choose Simulate Pause.

Finally, the dynamic scaling may be updated manually by choosing Edit Rescale Now.

Note	Updating dynamically scaled variables, implies the following: The min and max values of each variable are set equal to the variable's smallest and largest simulated value during the simulation, and all graphical reports containing rescaled variables are updated.

Fixed

Fixed scaling of a variable's min or max value means that the scaling is fixed to the value in the corresponding text box and is not affected by the simulation results.


Rescale Now (Edit menu)
Rescale Now

Use this command to rescale all variables that have dynamic scaling, as specified in the Edit Scale dialog box. All resulting presentations will then be updated.

Hint	Rescale Now is especially useful when you find yourself in the middle of a simulation run and the variables of your time graph have disappeared outside their current scaling ranges.


Find (Edit menu)
Find

Use this command to quickly locate a variable or snapshots of a variable in your model. When selected, the Find dialog box appears.

Hint	This operation is especially useful when dealing with large models.

Find dialog box

Names

Select the variable you want to locate.

List Categories

Choose between the two different search modes: "All variables" and "Variables with snapshots".

All Variables

In this mode, the Names list contains all the variables in the model. To locate a variable, simply select it in the Names list and hit Find.

Variables with Snapshots

In this mode, the Names list contains only the variables whereby one or more snapshots exist. To locate the snapshots of a variable, select the variable in the Names list and repeatedly hit Find Next.

Find/Find Next

Starts a search according to the selection in the Names list. If the current category is "All variables", the button is labeled "Find" [image]. Pushing the Find button starts a search for the selected variable. When the variable is found the button will change to "Find Next" [image] if the current variable has snapshots. Pushing the button will then start a search for the next snapshot. When all snapshots are found, the button is disabled.

Note	If the current category is "Variables with snapshots", the button text is "Find Next" from the beginning.

Find in Diagram view

When a variable is found, the diagram is scrolled so that the variable is located inside the diagram window, as near the center as possible.

Cancel

Closes the dialog box. The selection in the diagram remains unchanged.


View Menu

Use this menu to show or hide the commandbar and statusbar and to shrink or enlarge the diagram.

Overview of View menu commands

Commandbar - Toggles the commandbar on/off

Statusbar - Toggles the statusbar on/off

Zoom - Enlarges or reduces the contents of the active diagram window


Commandbar (View menu)
Commandbar

Use this command to display and hide the commandbar, this also includes buttons for some of the most common commands in Powersim, including Run, Pause, and Stop. A check mark appears next to the command name when the commandbar is displayed.


Statusbar (View menu)
Statusbar

Use this command to display and hide the statusbar. This bar contains various kinds of status information for example, context-sensitive menu help and current simulation time.


Zoom (View menu)
Zoom

Use this command to choose magnification or reduction for the active diagram window. A dialog box will appear when you select this option.

Hint	You may also use the zoom buttons found in the commandbar:


Zoom dialog box

Zoom (%)

A drop down list for setting the magnification or reduction of the diagram. The zooming is expressed in terms of percent of the normal magnification (100%). You may specify any percentage between 6.25 and 400. The upper limit may be reduced in very large diagrams due to limitations in MS-Windows. Attempts to select a too large percentage will result in an error message.

Fit To Window

Zooms the diagram to fit the current window.


Zooming a window to cover current area only

You may zoom the active window to cover only a selected part of a diagram by first creating an area and then pushing Zoom in [image] on the commandbar.

To zoom a window to cover current area only

1	Draw a frame around the desired part of the diagram using the right mouse button.

2	Hit Zoom in [image].


Simulate menu

Use this menu to start, stop, or pause a simulation, and to inspect/specify run and simulation parameters, including time step and integration method.

Overview of Simulate menu commands

Run - Starts a simulation

Run Step - Runs a simulation one step or initializes a new simulation run

Pause - Toggles pause on/off

Stop - Stops a simulation

Clear Results - Clears stored simulation results

Run Setup - Defines run parameters

Simulation Setup - Defines simulation parameters (start, stop, time step, etc.)


Run (Simulate menu)
Run

The Run command starts a new simulation run. The command is disabled while a simulation is running.

To quickly start a simulation, click Run [image] on the commandbar.


Run Step (Simulate menu)
Run Step

The Run Step command simulates one time step forward from the current (paused) state and then pauses the simulation (again). If a simulation run was not started or initialized when Run Step was chosen, a new simulation run is initialized and put in pause mode. In this case choosing Run Step will not advance the simulation and is therefore equivalent to choosing Pause and Run in sequence. Run Step runs the simulation stepwise independently of the settings in Simulate Run Setup.

To quickly run a simulation one step or initialize a new simulation run, click Run Step [image] on the commandbar.


Pause (Simulate menu)
Pause

The Pause command switches the pause mode on or off. When pause is on, a checkmark is displayed on the menu and the Pause button on the commandbar (if present) is depressed [image].

To quickly pause or resume a simulation, click Pause [image] on the commandbar.


Stop (Simulate menu)
Stop

The Stop command stops a running simulation. The command is disabled if no simulation is running.

To quickly stop a simulation, click Stop [image] on the commandbar.


Clear Results (Simulate menu)
Clear Results

Use this command to clear all simulation results in the current document. This will restore the contents of all presentations, as if no simulation had taken place.

Choosing Clear Results will also make auto reports disappear from your diagram (if visible).


Run Setup (Simulate menu)
Run Setup

Use this command to define automatic pause settings, the number of sequential runs, and a possible imposed delay time for each simulation step. A dialog box will appear when you choose this option.

Run Setup dialog box

Auto Pause

Use this group of radio buttons to specify criteria for automatic pauses in the simulation run. When the conditions for an auto pause are fulfilled, Powersim will automatically switch pause on. The Pause button on the commandbar (if present) will then be set to a pushed state and the Pause entry on the Simulate menu will be checked. When you switch pause off, the simulation will run for another auto pause interval. In this way you may run a simulation in desired "time portions" until the stop time is reached.

Note	The auto pause feature also allows you to adjust model parameters or inspect temporary simulation results in the middle of a simulation run. See also: Using the Auto Pause Facility .

Never

The simulation will run continuously from start time to stop time, as specified in the Simulation Setup dialog box.

Every <n> Time Units

The simulation will run for the given number of time units and then pause. (One Time Unit equals 1/Timestep steps.)

Every <n> Time Steps

The simulation will run for the given number of time steps and then pause. (If the specified auto pause time exceeds the stop time, the auto pause will not occur.)

Runs

Type or select the desired number of sequential simulation runs to be carried out. The default value is 1.

Delay (ms / time step)

Type or select the number of milliseconds (ms) that you want the simulation to be delayed between each time step. The default value is 0 or maximum simulation speed.

Hint	The ability to reduce the speed of a simulation by imposing delays between time steps can be useful for several reasons. For example, if you have small models which normally run very fast, you may want to slow down their speed so that you can follow the development of their simulations as they proceed. This feature also gives you the opportunity to adapt simulations to real-time conditions.


Using the Auto Pause Facility

Sometimes you wish to pause a simulation run at a specific point in time in order to change a parameter or inspect simulation results at that point. Powersim offers an easy way of doing this: Auto Pause.

To make Powersim automatically pause a simulation

1	Choose Run Setup from the Simulate menu.

2	Type a number, let's say 5, into the Every <n> Time Units text box.

3	Hit OK.

When the simulation reaches time 5, Powersim will now automatically switch pause on. The Pause button on the commandbar (if present) will be set to a pushed state and the Pause entry on the Simulate menu will become checked. When you switch pause off again, the simulation will run for another auto pause interval. In this way you may run a simulation in desired "time portions" until the stop time is reached.


Simulation Setup (Simulate menu)
Simulation Setup

Use this command to inspect simulation times, integration method, time step, and connected co-models. A dialog box will appear when you choose this option.

Simulation Setup dialog box (read-only)

Model(s)

Displays the models that the current settings apply to.

Times

Displays the time attributes for the current model.

Start Time, Stop Time

Displays the start and stop times for the simulation.

Time Unit

Displays the time unit for the main model (if present).

Integration

Displays the integration method, time step, and if a variable step size method is chosen, error limits.

Method

Displays the selected integration method. Available methods are Euler fixed step, Runge-Kutta 2, 3, and 4 fixed step, and Runge-Kutta 4 variable step.

Time Step

Displays the time step for the current model.

AbsError, RelError

Displays the absolute and relative integration error limits.

Set

Confirms the current settings.

Co-models >>

Expands or compresses the dialog box. When expanded, the dialog box includes the Parallel Simulation group for inspecting co-models.

Parallel Simulation

This list displays the main model and the co-models to be simulated in parallel. It contains the following columns:

Model

Displays the name of the connected model.

Time Step

Displays the time step of the connected model.

Start Time, Stop Time

Displays the start and stop time of the connected model.

Note 	Co-models are simulated using their local time step, start, and stop settings, which may differ from those of the main model. If there are differences, Powersim will automatically synchronize the simulation so that the co-models still run in parallel with the main model.


Window menu

You use this menu to rearrange windows or activate specified windows.

Overview of Window menu commands

Cascade - Arranges windows in an overlapping pattern

Tile - Arranges windows side by side so that all windows are visible

Arrange Icons - Arranges all icons in rows

Close All - Closes all Powersim windows

<list of windows> - Lists open windows


New Window

Use this command to open an additional window with the same contents as the active window. You can then display different parts or views of a document at the same time. If you change the contents in one window, all other windows containing the same document reflect those changes. When you open a new window, it becomes the active window and is displayed on top of all other open windows.


Cascade

Use this command to arrange windows in an overlapping pattern so that the title bar of each window remains visible. Windows without scroll bars are not resized by Cascade and Tile.


Tile

Use this command to arrange windows side by side so that all windows are visible.


Arrange Icons

Use this command to arrange all iconized windows in rows.


Close All

Use this command to close all Powersim windows. This implies the closing of all open documents.


<list of windows>

The names of all available windows and window icons are listed at the bottom of the Window menu. To activate a window, choose its name from this list.


Help menu

Use this menu to get help on using Powersim.

Overview of Help menu commands

Contents - Displays the contents screen of Help

Getting Started - Displays the Getting Started screen of Help

Current Document... - Opens the Help file associated with the current document

About Powersim - Displays version number, copyright notice, and license info


Contents

Use this command to display the contents screen of Help. From this screen, you can jump to step-by-step instructions for using Powersim and various types of reference information.

Once you open Help, you can click the first button on the left in the Help window, labeled Contents, whenever you want to return to the opening screen.

Hint	To open Help on an active dialog box, press F1 on your keyboard, or click the dialog box's Help button [image].


Getting Started

Use this command to open a step-by-step description of how to run a ready-made simulator in Powersim.


Current Document:  command
Current Document...

Use this command to open a Windows Help file with the same file name as the current document. For example, if the current document is WORLD5.SIM, you may open WORLD5.HLP (if present) by choosing this command. If no help file with the same name as the current document is present on the current document's directory, this menu entry is disabled.

This feature enables you to supply each document with its own help file. Such help files will typically contain model descriptions, guidelines for running a game, etc.


About Powersim

Use this command to display the version number of your copy of Powersim, the copyright notice, and information about the user license.


Presenting Simulation Results

Simulation results may be presented by any of the methods listed in the table below. Presentations may be output only or both input and output. A presentation that receives input, allows you to interact with a running simulation, while presentations that are output only are used merely for displaying information about a simulation.

Name	Methods	Output	Input
Auto Reports	Number, animation, or graph	X
Array Graph	Presents an array of numbers in a two-dimensional graph	X	X
Button	Presents values as push buttons, check marks, or radio buttons	X	X
Gauge	Presents values as a moving bar or needle	X	X
Multi-Media	Presents video, animation, sound, text, pictures, or message boxes based on the state of a simulation	X	X
Number	Presents values as numbers	X	X
Scatter Graph	Presents two variables in a two-dimensional graph	X
Slider/Bar	Presents values as horizontal or vertical slider buttons or bars	X	X
Time Graph	Presents values as two-dimensional line graphs and/or areas	X
Time Table	Presents values as tables of numbers	X


Auto report
Auto Reports

Auto reports are presentations of simulation results automatically displayed within or next to variable symbols in a diagram. Powersim offers three auto-report methods:

Animation

Number

Graph (only available for levels)


Animation auto report

Levels are animated as vertical, hollow (non-filled) bars. (Compared to a filled bar animation, the non-filled variant of Powersim significantly increases the simulation speed.) The extent of the bar is determined by the variable's simulated value relative to its min and max values.

Auxiliaries and constants are animated as gauges, i.e., as needles with their center at the bottom of the variable symbol. A needle in the leftmost position signifies that the variable's value is less than or equal to its minimum value. A needle in the rightmost position signifies that the value of the variable is equal to or greater than its maximum value. Minimum and maximum values are specified from the Scale dialog box, opened from the Edit menu.


Number auto report

The variable's value is presented as a number, outside the variable symbol, at the side opposite of the variable name.


Graph auto report

The graph is drawn as a simple line graph inside the level rectangle. The line color follows the symbol color.


Array Graph

The array graph is an input/output presentation that displays an array variable or a series of scalar variables as a line graph or bar, optionally filled with a color.

Hint	The array graph is perfect for displaying the same kind of information at run time as can be done using the graph/vector editor at edit time.

Array Graph example

In the array graph below, the values of the elements of the array variable Temperature are presented as filled bars.


Button

A button presentation displays the current value of certain variables as one of the following button states: set, clear, or other. Buttons may be used to set variable values and values of control variables, such as Play and Pause.

Buttons may be displayed as push buttons, check marks, or radio buttons. The table below displays how the different button types are drawn in the three states.

State	Push Button	Check Mark	Radio Button
Clear
Set
Other


Gauge

The gauge is an input/output presentation which displays a model variable as a moving bar or needle. The gauge can appear in a countless number of ways, with different colors, shape, and axis.

Gauge example

In the example below, the value of the variable Speed is presented both as a gauge needle and as a number inside the gauge.


Multi-Media

This is a true multi purpose presentation that allows you to present video, animation, sound, text, pictures, and message boxes based on the state of a simulation. The multi-media feature is also an input presentation that allows the model to obtain information from a playing video, the user's response to a message, etc.


Number

 A number presentation displays the current value of a certain variable as a number. The number presentation to the left displays the current value of the variable Revenue. If the parameter associated with a number presentation is a constant or a level whose initial value is not dependant on other variables, you may adjust the value of the constant directly by clicking on the presentation and entering the desired value from the keyboard.


Scatter Graph

A scatter graph displays the relationship between two variables in a two-dimensional graph by using one variable as the X-coordinate and the other as the Y-coordinate.

Scatter Graph example

In the scatter graph below, the values of Capital and Consumption are plotted as the result of a simulation. Each point (X, Y) on the graph corresponds to a particular point in time where Capital = X and Consumption = Y.


Slider/Bar

A slider/bar presentation displays the current value of certain variables as bars and/or slider buttons along a horizontal or vertical value axis.

Slider/Bar examples

The slider/bar presentation below contains two variables. The variable Inventory is presented as a bar. The bar is output only. The variable Inv_Coverage, which is a constant in the model, is presented as a slider. The slider allows you to adjust the variable directly by dragging the button while a simulation is running.

A horizontally orientated slider/bar with labels positioned to the left and number boxes not present

A slider/bar presentation can also contain a number box for each parameter that allows you to see the precise numerical value as you adjust variables by dragging the slider button. If present, the number boxes are always positioned on the opposite side of their corresponding label.

A vertically oriented slider/bar with the label positioned on top and number boxes present


Time Graph

A time graph displays a graphical overview of one or more variables' development over time. It has Time as the variable along the x-axis, and one or more dependant variables along the y-axis.

Time Graph example

In the example below, the values of the variables Inventory and Shipments are plotted along the vertical (Y) axis of the graph.

Hint	If you double-click on a time graph while simulating (or pausing) the Display dialog box (see page ) will open.


Time Table

A time table presents the time series history of certain variables in columns or rows.

Time Table example

The time table below displays the history of the variables Balance and Interest.

Hint	If you double-click on a time table while simulating (or pausing) the Display dialog box (see page ) will open.


Display dialog box
Display dialog box (read-only)

The Display dialog box operates on simulation time series. It may be used to control which series is displayed by the current presentation, the plotting order, copying of time series data to the clipboard , etc.

Available Series

This option displays all variables for which the presentation stores simulated values. To add a series from this list to the Displayed Series list, double-click on the series or select it and hit Add [image]. The series already present in the Displayed Series list are disabled.

Displayed Series

This list contains the series that will be displayed by the presentation.

The plotting order is determined by the sorting of the list. If you use area drawing, some variables may be hidden by series plotted later. Changing the plotting order may be used to avoid this problem.

To remove a series from a plot, double-click on it or select it and hit Remove [image].

Add New Generations to Display List

Check this button if you want new generations of simulated values to be automatically added to the Display Series list. This option is switched off by default.

Note	This option will have no effect unless the author of the document switched on Simulation Starts New Generation while defining the presentation using the Powersim authoring version. When this check box is switched on, current time series of the Displayed Series list box will be stored under the next available generation number when a new simulation is started. A newly created series will be added to the Available Series list box. If the Add New Generations to Display List check box is switched on, new series will be added to the Displayed Series as well.

Copy

This option copies the time series data selected from the Displayed Series list so you can export them to other applications, such as spreadsheets or word processors. It also opens the Copy Time Series dialog box.

Order Available

Use this list to change the sorting order of the Available Series list.

Sort

Use this group to change the plotting order of the series in the Displayed Series list box.

Move Up, Move Down

Moves selected series in the Displayed Series list box up or down.

By Var

The contents of the Displayed Series list is sorted by variable name.

By Age

The contents of the Displayed Series list is sorted by age. The older generations are listed first.

By Max

The contents of the Displayed Series list box is sorted by max scaling value, which means that variables with higher max values (specify in Edit Scale) come first. If your presentation uses area drawing, this may reduce the problem of some variables hiding previously plotted variables.


Copy Time Series
Copying Time Series

Time series of simulated data may be copied to the clipboard from a time graph or a time table.

Copy Time Series dialog box

Orientation

Choose between Horizontal and Vertical orientation of the copied data.

Include

Use this group to determine whether or not you wish to copy the Title of the selected series and the corresponding Time values along with the copied data.

Time Range

Use this group to specify the time range for the data to be copied. Type or select the From time (the first time it copies a value), To time (the last time it copies a value), and time Step (the time between each copied value).

If you check the Auto boxes, which is the default, the copying will follow the simulation setup, which means that values will be copied each time step, from start time to stop time, as specified in the Simulation Setup dialog box.

OK

Copies the selected series according to the settings in the dialog box.


Terminology

Area

Clipboard

Co-model

Dt

Field

Flow

Inflow

Input Presentation

Integration method

Level

OLE

Outflow

Rate

Read-Only Dialog Box

Simulation

Snapshot

Time step


Area

A rectangular selection in a diagram that is created by pressing the right mouse button while dragging; a dotted frame shows the extent of the area. The contents of the area may be copied to the clipboard, allowing for export of OLE objects, bitmaps, or pictures to other programs.


Clipboard

The Windows clipboard provides temporary storage for information you want to transfer. You can cut or copy information from an application onto the clipboard and then transfer (paste) that information from the clipboard into other applications. The clipboard holds its current information until you perform a new copy operation.


Co-model

Powersim provides a means of synchronizing individual models during simulation (concurrent simulation). This is done by hooking co-models up to a main model, which then controls the simulation process of its co-models.


Dt

An acronym for "delta time", which means a certain addition or increment to time. In Powersim the term dt appears only in the definition of level variables. Example:

level Population = 100 +dt*Births -dt*Deaths

In this context it represents the integration interval used by Powersim when computing the values of the flows that change a level for each time step in a simulation. The time step is defined by the setting of Time Step in the Simulation Setup  dialog box. Provided that Euler is chosen as the integration method, dt may be considered equal to the time step (See also time step.)


Field

A field is a set of codes that can be used in the definition of Page Setup to retrieve and display various information from a document or from the computer's internal clock and calendar. For example, the FILENAME field retrieves and displays the filename of the current document.


Flow

A flow represents the idea of quantities being transported between level variables. Levels are changed by adding the values of inflows and subtracting the values of outflows from their current values. Since flows are added to or subtracted from levels, flows must have the same unit of measure as the connected levels. The value of a flow is therefore defined as the associated rate variable multiplied by the time step. When referring to the time-relative values of flows into or out of levels, we recommend the term flow rate (or simply rate).


Inflow

A flow which is running into a level, which means that the value of the flow variable multiplied by dt  is added to the level each time step in a simulation. Note that a flow may be both an inflow and an outflow at the same time.


Input Presentation

A result presentation that may receive user input during a simulation run.


Integration method

Integration is the process of adding the sum of the levels' rates of flow to the current value of the levels for each time step during a simulation. There are several methods, or algorithms, available for performing the integration in Powersim. The simplest, and most commonly used, is the Euler method.


Level

A variable type in Powersim models, used to represent the state variables of a system. Levels accumulate connected flows. Also called stock.


OLE

Stands for Object Linking and Embedding. In short, this means that entities from one application may be included in another application. For example, a Powersim diagram may be included in an Excel spreadsheet document.


Outflow

A flow which is running out of a level, which means that the value of the flow variable (multiplied by dt ) is subtracted from the level each time step in a simulation. Also note that a flow may be both an inflow and an outflow at the same time.


Rate

A variable that controls a flow. In Powersim all three variable types (auxiliaries, constants, and levels) may control flows. In other words, the term rate is not used to denote a variable type, since a variable of any type may be used as a rate.

A rate will always have a unit of measure relative to time. Such as, if the time unit is "Week" and a rate is controlling a level with "Products", the rate's unit should be "Products/Week".


Read-Only Dialog Box

This dialog box is "read-only", meaning that some, or all editing actions in the dialog box, are disabled. The dialog box may still be useful for inspecting the various settings.


Simulation

The process of conducting experiments on a model instead of attempting the experiments with the real system. Technically, simulation portrays the development of the variables of a system over time. The simulation time is divided into small steps, and mathematical techniques from integral calculations are used to update the current state of the system for each step.


Snapshot

A variable symbol with an extra set of corners to indicate that it is an identical copy of another variable. Snapshots are useful for linking variables located in different parts of a model.


Time step

The time increment for each step of the simulation, as specified, in the Time Step text box of the Simulation Setup  dialog box.