This project demonstrates how to interface a System Under Test for TTCN (SUT)
with the generated code for the TTCN test as generated by PragmaDev Tester.

The interface is defined in the file tRequestAnswer.ttcn3 via the component
declaration. The component named mtc_type contains one "port", with the type
"message", and defining two messages:
  - mRequest, outgoing for the test, so incoming in the SUT;
  - mAnswer, incoming for the test, so outgoing for the SUT.

The SUT is implemented via a single function, called handleRequestMessage,
declared in SUT.h and implemented in SUT.c. It just accepts a struct
representing the mRequest message, computes the corresponding mAnswer and sends
it back to the test, seen as the environment from the SUT, via the function
sendAnswerMessageToEnv (also declared in SUT.h, but implemented in
RTDS_TTCN_SUT_interface.c).

Apart from this declaration, RTDS_TTCN_SUT_interface.c also defines the function
SUT_init, which is called at system startup to actually start the SUT. Here, it
only creates a message queue to allow the SUT and the test to communicate. The
function to call is defined at compile-time via the macro RTDS_TTCN_SUT_INIT set
in the compiler options in the generation options.

All functions and macros whose name starts with RTDS_ are provided by the
application, either as predefined functions or as generated code. The basic
principles for TTCN / SUT interfacing are described in the Reference Manual,
section 15.6.
