FPGA (field programmable gate array) detection method for fiber-cut and power-cut alarming of PDH (plesiochronous digital hierarchy) device

Abstract

The invention discloses an FPGA (field programmable gate array) detection method for fiber-cut and power-cut alarming of a PDH (plesiochronous digital hierarchy) device, which relates to a PDH system and comprises the following steps: a, an idle channel is appointed between a first device and a second device which are connected through optical fiber and is used as a dedicated channel, and the first device and the second device are both PDH devices; b, the first device can emit a power-cut alarming signal through the dedicated channel when the first device is powered down; c, the second device detects the alarming signal through the FPGA and distinguishes that the first device is fiber-cut or power-cut by combining the no-light alarming information received by an optical module provided by the second device; if the power-cut alarming signal is detected, and then the no-light alarming information is received, and thus the first device can be judged in a power-cut condition; and if only the no-light alarming information is received, but the power-cut alarming signal is not detected, and thus the first device can be judged to be in a fiber-cut condition. According to the method, the influence that the alarming signal is mixed up with messy codes is avoided, the situation that whether the opposite terminal device connected with the optical fiber is in fiber-cut condition or in a power-cut condition can be accurately distinguished, and the failure recovery time can be saved.

Description

technical field [0001] The present invention relates to a PDH (Plesiochronous Digital Hierarchy, quasi-synchronous digital sequence) system, specifically an FPGA (Field-Programmable Gate Array, Field-Programmable Gate Array) detection method for PDH equipment fiber cut and power cut alarm. Background technique [0002] The PDH transmission network refers to a network based on quasi-synchronous digital equipment, which is mainly used at the edge of the transmission network. Usually, a number of transmission channels are reserved in the PDH network for data transmission such as management and maintenance signals between devices, network low-speed data services, and network management information. The data in these channels is multiplexed with service data and transmitted to the Peer device. [0003] In a PDH network, when a device at one end (such as a client) is powered off and the service is interrupted, an optical line unit in the device at the other end (such as an The n...

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Problems solved by technology

[0003] In a PDH network, when a device at one end (such as a client) is powered off and the service is interrupted, an optical line unit in the device at the other end (such as an The no-light alarm may also be caused by the failure of the optical line unit or the damage of the optical cable. Therefore, it is impossible to judge whether the fault is a broken fiber or a power failure of the peer device only by receiving the no-light alarm.

[0004] It is a common transmission method to send a dedicated alarm signal immediately before the device is completely powered off through the idle channel in the PDH network. Accurate detection is mainly manifested in the fact that the sent alarm signal will be mixed with garbled characters, which will cause the peer device to detect the wrong alarm signal

Therefore, it is difficult to judge whether the fiber is broken or the power is cut off. It is necessary to find out the cause through other means. The process is cumbersome and inconvenient for equipment maintenance, which greatly increases the recovery time of the fault.

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