The graphical user interface (GUI) (or you, the user) communicates with the STAAD analysis engine through the STAAD input file (file extension .STD). That input file is a text file consisting of a series of commands in the STAAD command language which are executed sequentially.
The commands contain either instructions or data pertaining to analysis and/or design. The elements and conventions of the STAAD command language are described in Technical Reference of STAAD Commands
The STAAD input file can be created through the graphical user interface (GUI) modeling facility or using the STAAD.Pro Editor. The graphical modeling facility creates the input file through an interactive, graphics oriented procedure. In general, any plain-text editor may be utilized to edit or create the STAAD input file, but the STAAD.Pro Editor is recommended.
Some of the automatic generation facilities of the STAAD command language will be reinterpreted by the GUI as lists of individual model elements upon editing the file using the GUI. A warning message is presented prior to this occurring. This does not result in any effective difference in the model or how it is analyzed or designed.
It is important to understand that STAAD.Pro is capable of analyzing a wide range of structures. While some parametric input features are available in the GUI, the formulation of input is the responsibility of you, the user. The program has no means of verifying that the structure input is that which was intended by the engineer.