The application relates to a
signal transmission method between a fire telephone main
machine and a fire telephone extension and a fire telephone
system, wherein a near-end optical transmission device is connected with the fire telephone main
machine, a far-end optical transmission device is connected with the fire telephone extension, the near-end optical transmission device is connected with the far-end optical transmission device through an
optical fiber; an
electric signal of analog audio data on a first fire telephone
bus is converted into an optical
signal by the near-end optical transmission device, and the converted optical
signal is transmitted through the
optical fiber; the signal transmission method between the fire telephone main
machine and the fire telephone extension and the fire telephone are ingeniously designed; the converted optical signal is transmitted through the
optical fiber; the optical
fiber has the advantages of low loss,
high bandwidth, strong anti-
electromagnetic interference capability and the like; the transmission distance of general optical signals can reach at least 20 kilometers; during the transmission process, the optical
fiber is not conductive, is not interfered by electromagnetic
waves, is less affected by resistance and
voltage, and the stable transmission of signals in a complex
electromagnetic environment is ensured.