The process of hardware configuration s involves several distinct but interrelated subtasks. The modules included in the actual hardware must be selected from among the available modules in the three series supported by Step 7 Lite. These include power supplies, analog input and output, CPUs, digital input and output, and specialized interface modules. The modules plug into specialized racks in the actual equipment. The corresponding software representations within Step 7 Lite must be interconnected and similarly located. In addition, hardware modules have parameters or programmable settings whose values must be set in order to make use of the various features of the hardware.
The hardware racks are graphically represented to the left of the Hardware Configuration pane, with a tabular format provided in the upper right. The tabular display shows details regarding each included module while the graphic display corresponds to the physical appearance and arrangement of modules within racks. The two views are synchronized, allowing users to review or manipulate the configuration within whichever view is most convenient or best fits their style of interaction. A graphic element connects the two views, thus facilitating interpretation by the user and enhancing the visual correspondence.
In the lower right is an available components catalog from which the hardware configuration can be constructed. The abbreviations and terms, such as PS, CPU and so on, are the familiar jargon of PLC programmers and Siemens users; the order of the catalog tabs reflects a natural but not required order for task performance. The catalog closed cover allows selecting the component series of interest and provides a “starting hint” for the first-time user. (A Windows XP-style “balloon help” could be an effective substitute in future versions.
The user has full control over the level of detail in presented information. Pop- up “tool tips” provides additional information when the user pauses over a catalog entry.