CAAPE User's Manual - ALSTOM Signaling Inc.

Using Application Files7.5. EDITING APPLICATION FILESEdit an application file in the File View by right clicking on it and selecting Edit from itspopup menu, or by double clicking on its icon. Text files are opened in the default editorspecified in CAAPE's User Preferences. VPI Library files are opened in a special LibraryFile Editor dialog. LPC files cannot be opened directly. They must be created graphicallyand then exported into the application.7.6. VPI LIBRARY FILESVPI Library files contain libraries of Vital or non-vital application logic routines which canbe individually retrieved and used as compiler input. Their purpose is to provide genericapplication logic for commonly-used operations that might be performed in manyapplications. They can be written using generic variable names which are replaced bythe actual variable names when the logic is used. This allows the same set of logicstatements to be used in many applications without forcing the applications to use thesame variable names. Since the logic routines exist in a single library file which can bekept in a central location, they are more easily maintained and kept consistent across allthe applications that use them.Library files consist of one or more "library members" which are individually edited andretrieved by the Vital or non-vital compiler. Each library member has:• A unique identifying name to be used when accessing the member.• A member type (VPI or CSEX) which determines what kind of logic statements it canuse.• Optional descriptive records providing the creation and revision history of themember.• A set of application logic statements with optional generic names for some or all ofthe variables.Using a library member in application logic consists of naming the library file and thelibrary member to be used, and identifying the actual variable names to be substitutedfor the generic ones. The library member's logic statements are extracted from thelibrary file, the actual variable names are substituted for the generic ones, and thestatements are inserted into the application logic.P2512A, Rev. Oct/09 7–8 Alstom Signaling Inc.