7.7.1 How the software finds the screens for a device

To extend the device oriented user interface, it is important to understand how device drivers and the predefined user interface windows are linked together in the sat-nms software. Principally there are three steps from the device driver to the user interface:

1. Each device driver defines a variable called info.frame. The device driver sets this value to the name of the frame definition it expects.
2. The user interface software - when the operator clicks to a device icon - reads the frame definition file of this name in the dframes subdirectory which is usually located on standard installation in /home/satnms/dframes.
3. The frame definition file contains the list of screens (the names of the files defining the screen layouts). The user interface software builds a card folder like window from this information.