Page 759 - ExtendSim User Guide
P. 759

Data Management and Exchange 733
User interfaces for data exchange
• Theflowofdatacanbeone-directionalortwo-directional.Withtwo-directionaldataflow,a data change at the source affects data at the target and a change at the target affects data at the source. One-directional data changes at the target do not affect the source.
• Somemethodsrequirethattwowindowsbeopenatthesametime.Copy/Pasterequiresonly one window; you do not need to leave the ExtendSim dialog or application file open once the data has been copied. On the other hand, DDE linking requires that windows in both ExtendSim and the other application be open to complete the process.
• Acommunicationmethodthathaslivelinkssendsadataupdatemessagealongwiththe data. This means that as soon as the data at the source changes, the target is dynamically notified and can take the appropriate actions to react to the new value.
• Dynamic data linking is only used to access ExtendSim internal data structures, such as ExtendSim databases and global arrays. Other methods can be used either internally or externally (for instance, copy/paste from one ExtendSim dialog to another or copy/paste from ExtendSim to Excel).
The information is summarized in the following table.
Read/Write blocks
Dynamic Data Link (DDL)
Dynamic Data Exchange (DDE) Link
See Page
Data Open
Direction Window(s)
Live ExtendSim or
One way 1 One way 1 Two way 1 One way 1 Two way 2
No Both No Both Possible Both Yes Internal Yes External
Link External Required Application
☞ Most of the above methods are supported by an underlying industry-standard technology, as discussed in “Data source indexing and organization” on page 782.
The Clipboard is useful for passing information within ExtendSim and between ExtendSim and other applications on the same computer. The copy/paste action can occur before a simula- tion run, after the run, or when the simulation is paused. While the Edit menu’s Copy, Paste, and Duplicate commands work the same as in most applications, there are a few items you should note:
• When copying/pasting data tables or database tables:
• To copy all the data in a specific column of a data table or database table, click in the column’s title field so that the entire column is selected. Then give the command Edit > Copy Data.
• To copy all the data from all the columns in a data table or database table, click in the upper left corner of the table so that the entire table is selected, then give the command Edit > Copy Data.
How To

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