To target a wider spectrum of Time-Triggered(TT) implementations of hard real-time systems, we consider approaches for building component-based systems that provide a physical model from a high-level model of the system and TT specifications. The obtained physical model is thus suitable for direct transformation into languages of specific TT platforms. In addition, if these approaches provide correctness-by-construction, they can help to avoid the monolithic a posteriori validation. In this paper, we focus on the TT interface concept of the TT paradigm. And we present a method that transforms the interaction in classic BIP (Behavior, Interaction, Priority) Model into a TT interface by source-to-source transformations. The method is based on the successive application of two types of source-to-source transformations; Transfer functions internalisation and n + 1-ary connector to TT interface transformation. The first simplifies the connector transfer functions by modifying components automata. The second transforms connector with simple transfer function into TT interfaces.