The increasing complexity of Industrial Distributed Control Systems (IDCS) poses significant challenges, especially regarding strict real-time constraints of safety-critical systems. Traditional IDCS modelling using IEC 61499 prioritises functionality and device mapping over network communication and timing guarantees, leading to performance degradation. This work addresses this by extending IEC 61499 and introducing new modelling elements, namely messages and channels, for a formal description of network communication. This enables precise specification of packet transmission, facilitating systematic IDCS design that meets timing requirements. The methodology involves mapping logical messages to physical channels, supporting upfront timing verification using a correct-by-construction methodology. This systematic analysis reduces design cycle reiterations and potential errors. The contract-based design approach enables verification of timed execution through consistency checks and virutal integration testing. Practicality and scalability are demonstrated through various IEC 61499 applications, validating the timing properties and highlighting potential challenges. The systematic and certifiable approach significantly enhances reliability and efficiency of real-world manufacturing processes by mitigating the impact of non-determinism and communication delays.