The main use of DLLs in ATEasy applications is as PC board instrument drivers. Most PC board instrument drivers use DLLs to interface between the computer and the instrument. ATEasy allows you to call these DLLs from any ATEasy module.
With DLLs, you can also extend ATEasy into such areas as database I/O, statistical analysis, and more. DLLs can also be used when existing source code written in other programming languages, such as C or Pascal, needs to be used by an ATEasy application. This source code can be recompiled to a DLL and called directly by an ATEasy application.
Another reason for using a DLL is to gain speed when a critical area of the application requires the full speed of machine-level compiled code.