In order for operators with little or no programming knowledge to see if problems may be occurring with a driver, and acquire some insight into what the problems are, graphics are required for VTS communication drivers. These graphics can be drawn anywhere on the pages of the VTS application.
The ShowStats, ShowComm, CommIndicator, SetStats, and ErrorMsg modules are used for graphical display. ShowStats, ShowComm, and CommIndicator are actual graphics modules, while SetStats and ErrorMsg are support modules that provide the statistics and error messages that are displayed. All of these modules can be customized to suit each individual type of I/O device. For example, additional statistics and information can be included in the ShowStats and ShowComm windows; however, the standard displays are generally sufficient.
The ShowStats and ShowComm graphics are buttons labeled with whatever text labels the user specifies, or the defaults: "Show Stats" and "Show Comm". The CommIndicator is a box whose color indicates the status of the communications. The normal color and error color may be chosen when the box is drawn. These buttons can be drawn anywhere on the screen in the VTS application. All three graphic objects are described in detail in the VTS Developer's Guide (see "VTS Developer's Guide: 6: Drawing Tags").