Accelerated development of test interfaces to new devices is achieved with the DDTT by isolating the device-specific calls in "stub routines", which are compiled and linked into a separate DLL file. Linkage to the device-interface routines is established at run-time by demand loading the DLL functions. The DLL name and function name information is obtained from the device-specific grammar file.

The DDTT parser reads a test-case file and locates a @NEWALIAS command. The @NEWALIAS command contains the name of a DDTT grammar file for all commands prefaced with the specified new alias name. The parser uses the device grammar file name to map all device-specific commands to the correct DLL and function name within the DLL.