ExtendSim 7.0.3 released on July 1, 2008. If you are using ExtendSim 7.0.2, 7.0.1, or 7.0.0, download a free patch to 7.0.3.

Network licenses are available for ExtendSim. An ExtendSim Network License allows a specified number of simultaneous ExtendSim users in a network environment. For more details, see Licensing Options.

To allow others to access your model or the ExtendSim functionality across an internet or intranet, you need an ASP license.

You have the option to purchase an ExtendSim Maintenance Subscription when you purchase or upgrade ExtendSim (single user licenses only). Major upgrades (whole number version changes) released during your maintenance year will automatically be shipped to you. You will be invoiced annually to renew the Subscription so that you can continue receiving regular upgrades.

If you purchase a Network License, you will automatically be enrolled in an annual Maintenance and Support Plan.

Returns are accepted within 30 days of shipment.

		Package must be unopened.
		Request an RMA number from Imagine That Inc. or your ExtendSim Distributor prior to return.
		A 15% restocking fee applies. No refunds on shipping fees.

Imagine That! warrants the CD on which the Software is recorded to be free from defects in material or workmanship under normal use for 30 days after the date of initial delivery. During the 30-day period, you may return the CD to Imagine That! and it will be replaced, without charge, with other media containing the Software. After the 30-day period, registered users can request a replacement CD for $25. Such replacement of the CD is your SOLE AND EXCLUSIVE REMEDY in the event of a defect.

ExtendSim ships with two printed manuals - a User Guide and a Developer Reference (except as noted below). All ExtendSim products also include these manuals in online, pdf format.

Printed documentation is NOT included with the following ExtendSim products: Lab License, LT-RunTime, and Demo. These products do, however, include the manuals online in the form of pdf files that you can read, search, and even print.

The ExtendSim User Guide explains and provides examples of different simulation approaches. This manual has step-by-step tutorials and models that show you how to build, run, and analyze ExtendSim models. Other sections in the User Guide show you how to enhance the look of your models, add animation and costing, print, import/export data, and so forth. The Developer Reference discusses the parts of a block, gives an in depth discussion of ModL code and the source code debugger, provides programming tips, and lists all of the built-in functions.

You may also download the ExtendSim manuals.

Check out our abbreviated list of solutions that ExtendSim has helped achieve. Also, there are a number of case studies, papers, and articles published on the web and in magazines that discuss how ExtendSim (and Extend, as it was formerly called) is being used by others. References to ExtendSim can be found in a number of books as well.

To other ExtendSim users to see what they are modeling, go to the ExtendSim Exchange, a virtual meeting room to exchange ideas, discuss simulation techniques, post issues and solutions, and talk directly to other simulationists.

Our customers present papers independently of Imagine That, Inc. Unlike other simulation software companies, we do not pay our customers to write a paper. While we encourage our customers to present papers, we believe that the best interests of the simulation community are served by remaining neutral at academic conferences.

Accessibility features built into Imagine That Inc. products help federal agencies address the requirements of Section 508 Standards. To learn more about these features, view the ExtendSim Section 508 VPAT.

A Voluntary Product Accessibility Template, or VPAT, is a standardized form developed by the Information Technology Industry Council to show how a software product meets key regulations of Section 508 of the Rehabilitation Act. The act requires all agencies and departments of the U.S. federal government to make electronic information and technology accessible to federal employees and members of the public with disabilities.

Download an Upgrade Order Form. If you are using ExtendSim in an educational environment, download an Education Upgrade Order Form.

ExtendSim is upwardly compatible and will read in models built in earlier versions of Extend such as 6 and 5. However, ExtendSim 7 is not backwardly compatible. Models and blocks you build in ExtendSim cannot be read by earlier versions of Extend.

		New libraries and features replace “legacy”* libraries. Item library replaces BPR, Discrete Event, and Mfg (Manufacturing) libraries. Value library replaces Generic library. Rate library replaces Flow library. Animation 2D-3D library replaces Animation library. Built-in features in ExtendSim, as well as in the Item and Value libraries, replace Items (DB) and SDI Tools libraries. See the “v6 to v7 Equivalents” file located at ExtendSim7\Documentation for a list of each legacy block and the corresponding new block or feature. All the legacy libraries are in the folder \Libraries\Legacy. The legacy libraries allow you to run models built in previous versions. But the legacy libraries are no longer being supported and will not be available in future versions of ExtendSim. Use of legacy libraries should be avoided, especially when creating new models.
		ExtendSim Databases replace the Industry database that was included in Extend Suite and Extend Industry. The Industry database is furnished with ExtendSim so that you can run old models. However the Industry DB is no longer supported and will not be available in future versions of ExtendSim. Use of the Industry DB should be avoided, especially when creating new models. So that you don’t lose any stored data, an ExtendSim Database can import an exported Industry database file.
		ExtendSim Suite includes 3D animation. If you previously used Extend Suite 6, Proof Animation is included in your ExtendSim Suite upgrade. Proof Animation will NOT be automatically included in new (non-upgrade) purchases of ExtendSim Suite. Instead, it can be purchased separately.
		ExtendSim 7 can read Extend 6 and 5 libraries (including the legacy* libraries), as well as the models you built in 6 or 5. However: Because of extensive architectural changes, there is no automatic method to cause older models to substitute blocks in the new libraries for those in the legacy libraries, or to substitute an ExtendSim database for the Industry database. Models and libraries that have been saved in ExtendSim 7 cannot be read by older versions.
		When building models, you can combine blocks from the new ExtendSim libraries (Item, Rate, and Value) with blocks from the legacy libraries. However: You cannot connect blocks from the (new) Rate library to (legacy) Flow library blocks. It is preferred that you build models using just the new ExtendSim libraries - avoid using the legacy libraries when creating new models.
		Extend 6 products (Extend CP, Extend OR, Extend Industry, and Extend Suite) will be available for purchase for one year after the release of ExtendSim 7 (until December 31, 2008). The v6 prices are the same as for v7.
		The User Guide and Developer Reference have been rewritten.
		An abbreviated list of new features can be found on this web site. For a list of all the new features. see the ExtendSim command Help > What’s New.

In addition to its new name, there are major changes that will affect how you use ExtendSim now and in the future.
		Before you begin the installation procedure, backup your old Extend folder and files.
		Install ExtendSim 7 using the Installation Guide included with the upgrade package.
		If you have created models, custom libraries, and so forth: Copy your models to the ExtendSim7 folder. Copy your custom libraries to the \Libraries folder. Copy your Include files to \Extensions\Includes. Copy your DLLs to \Extensions\DLLs.
		You can now uninstall the old Extend application and files.
		If you decide to instead keep the old Extend application files, please note that: Only one instance of ExtendSim/Extend can run at a time. Once you have saved models and libraries in ExtendSim 7, they cannot be read by older versions. We do not provide technical support for older versions. See the ExtendSim command File > Update Launch Control (Windows only) to select which application (ExtendSim or Extend) will launch when a model or library file is double-clicked.

We can ship Extend 6 to you if you are working with others who are still using this version. However, you will pay ExtendSim 7 prices. We recommend you purchase a Maintenance Subscription with your license so you can get ExtendSim 7 sent to you at no charge when you are ready to upgrade. Otherwise, you will need to pay the full upgrade price. This offer will only be guaranteed for one year after ExtendSim 7 release; until December 31, 2008. After that time, Extend 6 may no longer be available.

Download the ExtendSim Demo. The ExtendSim Demo is a limited, working copy of ExtendSim you can also use as a Player to run ExtendSim models built by others. You also have the ability to:

		Explore the feature and capabilities of all four ExtendSim products: ExtendSim Suite, ExtendSim AT, ExtendSim OR, and ExtendSim CP.
		Use it as a Player to run ExtendSim models of any size and view simulation results.
		Build (but not save) models that contain up to 75 blocks.* (Automatic model construction using scripting is not available in the Demo.)
		Change (but not save) parameters in any size model.
		Add new blocks and change connection lines in small models (75 blocks or less; additions and changes are not saved).*
		Create new blocks and save them in libraries.
* Full versions of the ExtendSim products allow you to build models of any size, save changes to existing models and save the models themselves, print model worksheets, and use scripting to automatically construct a model.

ExtendSim LT-RunTime is a limited version of ExtendSim that has more saving and printing capability than the Demo version. It is designed for:

		Students building small (75 blocks or less) models for classwork.
		Potential customers who are evaluating the ExtendSim line of products and need more capability than the free Demo version.
		Customers who don’t have ExtendSim but want to run models built by others.

See License Options for complete details on the LT-RunTime.

The functionality of the Extend 6 Player has now been folded into the ExtendSim 7 Demo. It will read the model into ExtendSim 7 and allow you to run and make parameter changes to the model; just like the Extend 6 Player had allowed you to do. Download the ExtendSim Demo.

If you use screen shots that contain ExtendSim blocks on your web site or in any printed matter, please post or footnote this statement:

ExtendSim blocks copyright © 1987-2008 Imagine That Inc. All rights reserved.

You must get prior written permission from Imagine That Inc. before using any documentation from the ExtendSim manuals, blocks, Help, or the Imagine That Inc. web site in your documentation. Once permission is granted, please include this statement:

Portions copyright © 1987-2008 Imagine That Inc. All rights reserved.

If your blocks use copyrighted information from certain libraries in the ExtendSim products, your right to sell, give, or otherwise distribute the blocks you have developed is restricted. In that case, your blocks may only be sold, given away, or distributed to a recipient who has the same ExtendSim package that you used to develop your blocks. For more information, see the copyright notices at the front of the ExtendSim User Guide.

Access to technical support is provided to all registered users at no charge for the first 60 days after purchase. Upgrades to new versions are fee-based unless you opt for the Maintenance Subscription.

If you have multiple ExtendSim licenses on your computer (for example the Demo and full version), it is generally better to open the ExtendSim license you want to use first, then open the model. If you double-click on a model to open the application, it will open the last ExtendSim license installed.

		Open the ExtendSim library.
		From the hierarchical library name menu, select "Open Library Window".
		Or open the library in the Navigator window
		The library version number is in the upper left corner of the library window.

In ExtendSim 7.0.2a Network, we have added technology to prevent an issue where checking out an ExtendSim 7 license could alter an installed Extend 6 license. In earlier versions of ExtendSim (prior to 7.0.2a), when you check out a license, then check it back in, the registry entry would not always be cleared. This could sometimes cause the application to not allow you check out a license when you should be able to. If the following conditions are true:

		You do not currently have a copy of a Extend 6 Network client on your machine.
		Your machine is not configured as a server for ExtendSim or Extend on the network.
		You do not currently have a license of either Extend or ExtendSim checked out on your machine.

Then use this Registry Clear executable to clear the registry entry. You will now be able to check out and check in licenses.

The ExtendSim 3D environment accepts 3D objects in DTS format. Several common editors that support exporting a DTS object (with an added plug-in) are Milkshape, 3ds Max, and Maya.

If the 3D editor you are using to edit your existing objects does not have a DTS exporter, you will need to import the objects into an editor that does. Once you have the objects in a editor that supports exporting a DTS object, you can modify them for use in ExtendSim. 

For more information, see How do I create a new object for use in the ExtendSim 3D Window?

The ability to construct 3D objects is not built into ExtendSim.  To build a new object for use with the ExtendSim 3D window:

	The ExtendSim 3D environment accepts 3D objects in DTS format. Use a 3D object editor that supports exporting objects in the DTS format. Most editors do not have a native DTS format ability, so this will involve adding an exporter plug-in to the editor. Several common editors that support exporting a DTS object (with an added plug-in) are Milkshape, 3ds Max, and Maya.
	Create the object in the editor. While designing the object, keep in mind different types of objects have different requirements. For example, an ExtendItem (an item that travels from block to block) should have a mount point on the top and bottom. To learn more about requirements for DTS objects, see the ExtendSim Developer Reference.
	Export the object from the editor to a DTS file. DTS objects have certain requirements. As an example, all DTS objects used by the GarageGames Torque engine require a bounding box. The exporter plug-in will, in some cases, provide the ability to add a bouding box automatically.
	Add the exported DTS file and associated texture files it requires into ExtendSim. Information about adding an object to the ExtendSim extensions folder is available in the ExtendSim Developer Reference.

This is a simplified description, as each of these steps is potentially complex, but complete otherwise.

For more tips on creating 3D objects, consider Creating Game Art for 3D Engines
(written by Brad Strong, published by Charles River Media). It covers the use of 3DS Max to build objects for the Torque engine (the engine the ExtendSim 3D window is based on).

Feel free to contact support@extendsim.com for questions about this process.

In other simulation tools, the items (AKA entities or transactions) are put on the event calendar (scheduled for future consideration when a time delay is encountered). In ExtendSim, the blocks have an entry on the event calendar. Some blocks contain their own event calendars with an entry for each item in the block.

Scheduling the blocks rather than the items has a number of advantages:

		Because there are typically fewer event scheduling blocks in the model than there are items to be scheduled and the number of event scheduling blocks in a model does not change, the ExtendSim event calendar is relatively small. This eliminates the need for time consuming insertion and deletion of events on the calendar. This is particularly important in large model where searching the event calendar for the next event can be a large portion of the execution time.
		It is very easy to change the event time. Because the block’s event time is stored in a fixed location, the future event time for the block can be changed with a simple assignment.
		Items are not necessary for an event. A block can schedule an event without needing to create (and then dispose of) an item.
		Any block in the model can schedule an event. This makes it particularly easy to build modeling components which simulate system features such as preemption and reneging. These types of features normally require internal or dummy items in other simulation tools.

ExtendSim uses both a push and pull mechanism to propel the items through the model. Residence blocks (residence blocks are any block that can hold an item for a non-zero amount of time) attempt to pull items in until it is full or until there are no more items to pull in. Then the residence blocks will try to push items out until there are no items left or the downstream path is blocked. In some cases, the residence block will hold the item for a specific time delay before attempting to push the item out.

The item waits in the last upstream residence block. Residence blocks are any block that can hold an item for a non-zero amount of time. Examples include queues, activities, resource blocks, and some decision blocks. If the last residence block is a generator type block, the item will be held until a new item is created or the activity pulls the item. This is the only time that an item will be destroyed if there is downstream capacity.

Yes, ExtendSim puts the blocks on the event calendar in simulation order. Blocks with a lower simulation order will receive their event message first. You can change the simulation order with the following steps:

		Go to Run > Simulation Setup > Continuous tab.
		Turn on Show Simulation Order from the Model menu.
		Select an event scheduling block and choose Set Simulation Order from the Model menu.
		Note that the simulation order will only make a difference if two or more events occur at exactly the same time. If the events are not exactly at the same time, the events will occur in chronological order.

1. Are there any caveats to how I can use the RunSimulation, PauseSim, and ResumeSimulation functions?
   These functions are not recommended for use via OLE automation or DDE Execute messages at all. These functions were developed before the External Scripting functionality was fully developed, and they do not work as well in this context as the ExecuteMenuCommand function. This function acts exactly as if you have selected the specified command from the menu bar and will perform better with the external control methods. The ExecuteMenuCommand function takes one argument, the command number. These numbers are defined in the Programmer Reference.
2. Should I do things differently if I am running a simulation that basically finishes instantly versus running a simulation that will run for longer which I want to control interactively?
   There is a difference in how you should set up your code in these two cases. If the simulation is going to complete instantly and/or you are not interested in sending other commands to ExtendSim while the simulation is running, you can just send the executeMenuCommand(6000) to ExtendSim without a worry. If, however, you are interested in running a longer simulation, and you want to be able to pause and resume it or get data while the simulation is running, you should use the IPCServerAsync(TRUE); function. This function specifies to ExtendSim that the following Execute control action should execute asynchronously, not synchronously. A synchronously executed instruction will execute immediately and the application that sent the command will wait for the instruction to complete before it continues its execution. An async command, on the other hand, will return immediately allowing the application to continue on with other things while the simulation runs. The sequence of instructions you should execute in this case would be as follows:

1.	IPCServerAsync(TRUE);
2.	ExecuteMenuCommand(6000);
3.	IPCServerAsync(FALSE);

These should be sent as three different execute messages. It is important to send the final IPCServerAsync(FALSE) and not to send any other Async messages while the simulation is running, as ExtendSim doesn't allow multiple asynchronous messages to be processed simultaneously.

If you add new dialog items or static variables, they will need to be initialized. The easiest way to do this is in the on openModel message handler. This is called whenever a model is loaded. If you delete or change the dimensions of dialog items or static variables the data in the existing blocks may not match up correctly with the data in the existing blocks. To avoid this, delete the existing blocks and re-add them to the model. You can also use the "hide" feature to hide the dialog item. You should do this if your blocks are being used in models where it would be inconvenient to replace each instance of the blocks.

You may need to update your copy of Carbon Lib, an extension allowing OS X applications to function properly under OS 9. You can update Carbon Lib by using Software Update under your Apple menu.