Optical fiber blocking override-avoiding tripping system

The invention discloses an optical fiber blocking override-avoiding tripping system and a blocking signal processing method for realizing an override avoiding function. The system comprises two types of devices, the first type is microcomputer synthetic protective devices PA 61 with the override-avoiding tripping function, and the second type is override-avoiding optical fiber hubs SU20. Optical blocking signals are used for connection blocking among the microcomputer synthetic protective devices and between the microcomputer synthetic protective devices and the override-avoiding optical fiber hubs. The states of the signals comprise a normal working state and 1-10 levels of time delay blocking states. The states of the signals are distinguished according to different frequencies of the signals. The frequencies of the signals are generated by an FPGA (Field Programmable Gate Array), and the FPGA outputs blocking signals with different widths to a DSP (Digital Signal Processor) when the FPGA communicates with the DSP. The system can realize the override-avoiding tripping of an upper level power supply system and a lower level power supply system, and can also realize multi-point concentration. The override-avoiding tripping is realized by the mode of unified blocking signal sending.