Rockwell Automation 8520-9API 9/Series OCI API Developer's Guide - Manual (Page 27)

3–6 OCI Basic Display Set (BDS)
Publication 8520-6.6 - August 1999
The majority of the 9/Series or 9/PC Basic Display Set screens are
laid out using a combination of overlaying forms. The forms used to
build a typical 9/Series or 9/PC screen include:
System Information
Display Form
PAL/Logic Messages Form
Softkey Area
Main MDI Form
•
Main Form (MAINMDI.FRM) – This form provides the structure
for all the 9/Series or 9/PC screens (MDI parent form). It defines
the size and layout, initializes global variables, loads system
information form, PAL/Logic message form, and softkey form.
Other forms overlay this form to provide the proper display.
•
System Form (SYSTEM.FRM) – This form overlays at the top of
the Basic Display Set screen. It is used to display system
messages and prompts for input information. It also manages
keyboard input. This form is loaded by MAINMDI.FRM.
•
Display Form (screenname.FRM) – This form overlays the center
portion of MAINMDI.FRM. It is different and specific for each
9/Series or 9/PC screen to be displayed. The Program Position
Screen (PROGPOS.FRM) is an example of a display form. The
PROGPOS.FRM differs from other display forms in that it
remains loaded in background anytime the Basic Display Set is
running. This improves performance since this screen is the most
commonly used display form. Typically, display forms are
loaded and unloaded by the softkey modules.
Basic Display Set Screen
Construction