Cabled seafloor observatories play an important role in ocean exploration for its long-term, real-time, and in-situ ob-
servation characteristics. In establishing a permanent, reliable, and robust seafloor observatory, a highly reliable cable switching
and  fault  isolation  method  is  essential.  After  reviewing  the  advantages  and  disadvantages  of  existing  switching  methods,  we
propose a novel active switching method for network configuration. Without additional communication path requirements, the
switching method provides a way to communicate with a shore station through an existing power transmission path. A coded
voltage signal with a distinct sequence is employed as the communication medium to transmit commands. The analysis of the
maximum  bit  frequency  of  the  voltage  signals  guarantees  the  accuracy  of  command  recognition.  A  prototype  based  on  the
switching method is built and tested in a laboratory environment, which validated the functionality and reliability of the method.

关键词： Cabled seafloor observatories,  Cable switching and fault isolation,  Coded voltage signal,  Maximum bit frequency