KR200269379Y1 - A detection device of trouble signal from optical signal receive system - Google Patents

Abstract

The present invention relates to a receiver for optical communication using an optical signal, and more particularly, to a failure signal detection apparatus, comprising: an optical receiver for receiving an optical signal from an optical cable; An optical receiver which is connected to an optical cable and outputs a clock signal and a data signal from the optical signal and outputs a fault signal of LOP, LOS and LOF; The characteristics of the PD are characterized by including a counter for receiving the LOP, LOS, LOF output signal from the optical receiver and receiving and counting clock signals from the outside and outputting the generated signals of LOP, LOS, and LOF. There is no need to make individual adjustments constantly, so it has mass production and uniformity of quality, and chattering does not occur in the boundary state caused by dark noise of PD.

Description

Fault signal detection device of optical signal receiver {A DETECTION DEVICE OF TROUBLE SIGNAL FROM OPTICAL SIGNAL RECEIVE SYSTEM}

The present invention relates to a receiver for optical communication using an optical signal, and more particularly, to a failure signal detection apparatus.

Optical communication devices transmit and receive communication signals using light, and are widely used due to advantages such as wideband characteristics of optical signals and long distance transmission using less energy.

The optical path of the optical communication equipment as described above transmits a large number of voice channel signals at the same time using a single line. Therefore, when a failure occurs, there is a problem in that a communication signal corresponding to a large number of voice channels cannot be transmitted at the same time. The maintenance is very important.

The optical communication equipment includes a Loss Of Signal (LOS) in which an optical signal to be transmitted is not received at a receiving side, a Loss Of Power (LOP) in which optical power is not received, and a LOF (Los Of Of Frame) in which a frame signal for synchronizing optical signals is not received. The relevant maintenance is performed by detecting or discriminating a fault alarm signal such as).

Hereinafter, a failure signal detection device of a conventional optical signal receiver will be described with reference to the accompanying drawings.

Attached to explain the prior art, Figure 1 is a failure signal detection device of the conventional optical signal receiving apparatus.

Referring to FIG. 1, the fault signal detecting apparatus of the conventional optical signal receiver includes an optical cable 10 for transmitting an optical signal,

The optical signal received through the optical cable is processed and output as a display signal. The optical signal applied from the optical cable 10 is detected and output as a current signal, and the current is converted into a voltage and output. At the same time, if the optical power is not detected PD (Photo Detect) unit 22 for outputting a LOP (Loss Of Power) failure signal;

A Limit Amplifier (LA) unit 24 for amplifying the voltage signal output from the PD unit 22 to output only a limited level and outputting a Loss of Signal (LOS) fault signal when an optical signal is not detected;

And a clock and data recovery (CDR) unit 26 for restoring a clock and data signal from the signal output from the LA unit 24 and outputting a loss of frame (LOF) fault signal when the data signal is not detected. It consists of the light receiving part which is made.

Hereinafter, a failure signal detection device of the optical signal receiver according to the prior art having the above configuration will be described.

When the electrical communication signal is transmitted as an optical signal through the optical cable 10, the optical receiver 20 converts the electrical signal into an electrical signal and outputs the electrical signal.

The PD unit 22 of the optical receiver 20 detects and converts an optical signal received from the optical cable 10 into an electrical current signal from optical power by using a photo diode (PD). Is converted into a voltage signal by TIA (Trans Impedance Amplifier) and output.

The PD of the PD unit 22 converts the optical power of the optical signal applied from the optical cable into a current signal and outputs the current signal. When the optical power is not applied, the PD generates a loss of power (LOP) fault signal.

The LA unit 24 amplifies the voltage signal output from the PD unit 22 and outputs only the constant level range. When the signal of the constant level is not output, the LOS (Loss Of Signal) Output fault signal.

As described above, the CDR unit 26 that receives the signal of a constant level output from the LA unit 24 analyzes the received signal and detects and outputs a clock and data signal. If not detected, outputs a LOF (Loss Of Frame) fault signal.

The failure signal detection apparatus according to the conventional configuration having the above-described configuration generates a failure alarm immediately upon detecting a failure signal such as LOP, LOS, LOF, etc. output from the optical receiver 20.

However, in the prior art as described above, the failure signal is dependent on the functions of the PD unit 22, the LA unit 24, and the CDR unit 26, and the PD unit 22, the LA unit 24, the CDR as described above. The unit 26 has a problem that depends greatly on the characteristics of the photo diode (PD).

Therefore, in order to make the characteristic constant, each PD needs to be precisely adjusted so that a constant output is generated, and there is a problem that it is difficult to apply to mass production and at the same time takes a lot of production cost.

In addition, even when the output of the PD is adjusted to be constant, since the setting of the reference level at which the fault signal is generated is arbitrary, in the boundary state near the threshold for distinguishing the fault signal, the chattering continuously repeats the fault state and the normal state. There is a problem that occurs.

An object of the present invention is to provide an apparatus for detecting an error signal of an optical signal receiver, which does not individually adjust each PD and prevents chattering in a boundary state.

The present invention devised to achieve the above object is an optical receiving device for receiving an optical signal from an optical cable; An optical receiver which is connected to an optical cable and outputs a clock signal and a data signal from the optical signal and outputs a fault signal of LOP, LOS and LOF; It includes a counting unit for receiving the error signal of the LOP, LOS, LOF output from the optical receiver and at the same time receives the clock signal from the outside and counts to output the generated signal of the LOP, LOS, LOF.

1 is a failure signal detection apparatus of an optical signal receiver according to the prior art,

2 is a functional block diagram of a failure signal detection device of the optical signal receiver according to the present invention.

** Explanation of symbols on the main parts of the drawing **

10,15: optical cable 20,25: optical receiver

22: PD part 24: LA part

26 CDR portion 30 Counter portion

Hereinafter, a failure signal detection device of an optical signal receiver according to the present invention will be described with reference to the accompanying drawings.

Attached to explain the present invention, Figure 2 is a functional block diagram of the failure signal detection device of the optical signal receiving apparatus according to the present invention.

Referring to FIG. 2, the fault signal detecting apparatus of the optical signal receiving apparatus according to the present invention includes an optical receiving apparatus for receiving an optical signal from an optical cable.

Outputs a clock signal and a data signal from an optical signal input by connecting to the optical cable 15 and receives a LOP (Loss Of Power) fault signal and a communication signal indicating that optical power is not received. An optical receiver 25 for outputting a LOS (Loss Of Signal) fault signal that does not appear, and a LOF (Loss Of Frame) fault signal that does not detect a clock and data;

The optical receiver unit receives the LOP, LOS, and LOF error signals output from the optical receiver 25, and receives and counts a clock (CLK) signal from the outside to output the generated signals of the LOP, LOS, and LOF. Outputting an LOP generation signal when the LOP failure signal outputted from (25) lasts for a predetermined time; Outputting an LOS generation signal when the LOS failure signal output from the optical receiver 25 lasts for a predetermined time; And a counter for outputting a LOF generation signal when the LOF failure signal output from the optical receiver 25 lasts for a predetermined time.

Hereinafter, the fault signal detecting apparatus of the optical signal receiving apparatus according to the present invention having the above configuration will be described in detail with reference to the accompanying drawings.

The communication signal of a very large number of subscribers is transmitted through the optical cable 15, and the communication signal transmitted by the optical signal as described above should be normally received without an error at the receiving side.

In order to confirm that the communication signal is normally transmitted as described above, the optical receiver 25 checks whether the optical power is detected in the process of receiving the optical signal, and if the optical power is not detected, the LOP (Loss Of Power) fault signal. Outputs

In addition, it is checked whether a communication signal is detected even when the optical power as described above is detected. If no communication signal is detected, a LOS (Loss Of Signal) fault signal indicating that no communication signal is detected is output.

Also, when the communication signal is detected as described above, it is checked whether the clock signal and the data signal are detected. If the clock signal and the data signal are not detected, the clock signal and the data signal are not locked or synchronized. Outputs a LOF (Loss Of Frame) fault signal indicating that

The optical receiver 25 outputs a normal communication signal to a corresponding processing unit when the failure signals of the LOP, LOS, and LOF are not generated, thereby allowing communication to proceed.

When the above-mentioned failure signals of LOP, LOS, and LOF are generated and output from the optical receiver 25, the counter 30 receives the LOP, LOS, and LOF failure signals at the same time. A clock (CLK) signal that is a reference to operate is input together.

The counting unit 30 outputs the corresponding LOP generation signal, LOS generation signal, and LOF generation signal when the failure signals of the LOPs, LOSs, and LOFs, respectively, are input for more than a predetermined time.

A code program for performing the above functions in the optical receiver 25 is, for example, as follows.

LOS detection logic

library IEEE;

use IEEE.std_logic_1164.all;

entity los_detection is

port (rx_los: in std_logic;

ref_clk: in std_logic

);

end los_detection;

architecture logic of los_detection is

signal counter, los_counter; std_logic_vector (8 downto 0);

begin

process (ref_clk)

begin

if rising_edge (sysclk) then

if counter = X "FF" then counter <= X "00";

else rx_los = '1'then los_counter <= los_counter +' 1 ';

end if;

end if;

if rising_edge (ref_clk) then

if los_counter = counter then los <= '1';

else los <= '0';

end if;

end if;

end process;

end logic;

Therefore, as in the prior art, it is not necessary to make individual adjustments in order to make the characteristics of the PD constant, and there is an advantage that the disturbance signal does not cause chattering due to the dark noise of the PD in the boundary state.

The present invention having the above-described configuration, in the optical signal receiving apparatus, does not have to adjust the characteristics of the PD constantly, thereby producing mass productivity and uniformity.

In addition, the chattering phenomenon that occurs in the boundary state due to the dark noise of the PD does not occur.

Claims (3)

In the optical receiving device for receiving an optical signal from an optical cable, An optical receiver connected to an optical cable to output a clock signal and a data signal from the optical signal and to output a fault signal of LOP, LOS, and LOF; Optical signal characterized in that it comprises a counter for receiving the error signal of the LOP, LOS, LOF output from the optical receiver and at the same time receiving and counting the clock signal from the outside to output the generated signal of the LOP, LOS, LOF Disturbance signal detection device of receiver. The method of claim 1, wherein the counting unit, If the LOP failure signal output from the optical receiver lasts for a predetermined time, and outputs the LOP generation signal, If the LOS failure signal output from the optical receiver lasts for a predetermined time period, and outputs the LOS generation signal, And outputting a LOF generation signal when the LOF failure signal output from the optical receiver is set for a predetermined time. According to claim 1, The clock signal received by the counter unit counts whether a fault signal of LOP, LOS, or LOP lasts for a predetermined time, and is a reference clock signal of the optical receiver unit. Signal detection device.