Change: Changes Your Model During a Run
With a Change Object you can make changes in your model whenever an item passes through it during a model run.
You use a Change Object to dynamically influence your model’s behaviour.
Change Objects enable you to construct wide-ranging and complex system control and management structures in your model, and more sophisticated or detailed animation.
A Change object is always idle.
A Change Object can be classified as “Logical Only.
It only operates when an item flows through it.
Change objects are the primary means by which you work with attributes in your model.
A Change object can perform sets of calculations (called Routines) that reference and modify Attributes, which can in turn determine the behaviour of other objects like Switches, Multi-Servers, etc. This kind of programming activity is event-based, and thus very flexible.
Change objects can alter an Item's Icon, by referencing an Index Number.
Change objects also enable you to read and write attribute or table information to/from text files during your model run.
They can also assign routes used for Rail network modelling, and perform queries and operations that read and write from ODBC Data sources.
Attributes can be changed when an item passes through a Change object.
The application of Attributes in this fashion enables wide-ranging and complex system control and management structures to be simulated.
Attributes can also collect details about the logical behaviour of your model and present them as on-screen and/or logged statistics.
Changes to an Item Attribute occur as the item passes through the Change Object, and affects only that individual Attribute of that individual item that is passing through the Change.
Changes to a Portal Attribute, System Attribute, Class Attribute or Table Attribute occur as the item passes through the Change, and its new value is "detected" at that time by any object that makes reference to that Attribute.
Changes to Attributes can be specified through the use of a range of Routine Operations that are entered into the Change Object.
Any of these operations can use a Constant value, or an Attribute, Table, or other types of data for reference.
Refer to the Routine Editor page for detailed information about available Operations.
You can use this option to choose an icon to apply to the item passing through the Change Object.
The Icon option in the Change Object Menu enables you to change Item icons according to an INDEX, which can be a reference to an Attribute Value.
- For full details refer to this page: Changing an Item's Icon
Any item passing through a Change Object set up for Data Exchange triggers a Data Exchange event.
There are a number of options for data transfer using a Change Object.
Data can be both imported and exported during a Model Run.
The exported data comprises the the current value of selected attributes, and Tables.
Imported Data is assigned to various Attributes, or Tables.
You can select the Attributes that you wish to write, using the Attribute Selection Dialog.
For more details on implementing Data Exchange, refer to: Data Connectivity and Integration.
The item needs to pass through a change object in which a route is applied to it before it departs the portal to go on to the track.
Use the Route option in the change object and you can build up a list of routes in a Route Assignment Table.
Enables Data Exchange with Databases that support the ODBC protocols.
Refer to the ODBC Data Exchange page.
Refer to Editing Object Properties for information about editing properties common to all objects.
- Select File Transfer Mode
- Change Object File Options Choices
- Changing an Item's Icon
- File access error handling
- Routine Attribute
- Routine Operations Dialog
- Determining the last file read or written at a change object
- Executing a command in a minimised window
- Making a HTTP request from a URL
- Speeding up ODBC operations by keeping the connection open
- Icon Assignment Table
Change Object Frequently Asked Questions