In recent decades, the growing need for electric power has brought out the need to implement increasingly efficient and reliable automation and protection systems for electrical substations. The development of remote control and tele-conduction functions, which supports remote management plant, has also become a fundamental requirement in the operation of the electricity network. S.A.S. (Substation Automation Systems) are the new generation systems that perform the functions of protection, automation, control and which are designed based on the functional requirements of the IEC61850 Standard, having quickly become a key component of the energy transmission system. In this respect, this paper aims to highlight the importance of interoperability in the adoption of the process bus for the communication of the Merging Unit with the Protection Units and the advantages of the redundancy of the communication network using the Parallel Redundancy Protocol (PRP) and Highly-available Seamless Redundancy (HSR).