The eTT software package contains a test tool with which a defined set of test cases between the user medium (NM), secure application module (SAM) and a simulation terminal (ST) can be mapped. This allows a real user medium or SAM to be tested against the SAM or NM simulators implemented in eTT. The test tool maps the terminal processes that are relevant for the interaction between NM and SAM.

Although the user's own data or data structures must be syntactically correct, a user medium may, for example, contain an expired authorisation. Nevertheless, a terminal can be tested with it. For its part, the terminal can output new data structures (such as new authorisations) and carry out transactions. These changes can then be output in readable form with eTT and evaluated by the user.