An online optical power detection circuit and detection method with calibrated accuracy

Abstract

The present invention provides an online optical power detection circuit and detection method with calibrated accuracy, which can improve the accuracy of optical power detection. It includes an MCU chip, an optical power detection circuit; and an optical power calibration circuit; the optical power calibration circuit includes multiple optical power calibration circuits, each having the same circuit structure, and the number of the optical power calibration circuits is 2. n The circuit structure includes a fusible circuit structure. During calibration, the MCU chip performs the optical power calibration function, uses the standard light source as the optical signal input of the optical power detection circuit, and forms a binary calibration coefficient by controlling the fusible circuit in the optical power calibration circuit to open, so as to realize the solidification of the optical power calibration coefficient corresponding to the receiving fiber seat. The MCU chip program directly calls 2 n The optical power is calibrated by using a binary calibration coefficient of an optical power calibration circuit to realize an online optical power detection function with calibrable accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber communication, and in particular to an online optical power detection circuit and detection method capable of calibrating accuracy. Background Art

[0002] In fiber optic communication systems, the receiving fiber optic connector has certain requirements for optical signal strength. When the optical power is too low, the fiber optic communication signal may become unstable or even interrupted. Factors that may cause reduced optical power include the near failure of the transmitting fiber optic connector or the deformation of the optical fiber cable. In addition to the optical signal conversion pin, some models of the receiving fiber optic connector also include an RSSI pin, or received signal strength indicator pin. This pin can be used with peripheral circuitry to transmit optical power information to the MCU chip, which can be used for online optical power detection. However, due to the generally low accuracy of the RSSI pin (typically within a range of ±20%), using it directly as a criterion for engineering maintenance may result in a high probability of misjudgment. To facilitate engineering maintenance applications, the accuracy of optical power detection needs to be improved.

[0003] Although some models of receiving fiber optic sockets include a received signal strength indicator pin and can perform online optical power detection, the accuracy of the pin indication is low and cannot be directly used as a criterion for determining whether there is a failure and whether maintenance is required. Summary of the Invention

[0004] In order to solve the technical problem raised by the background technology, the present invention provides an online optical power detection circuit and detection method with calibrable accuracy, which can improve the accuracy of optical power detection.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] An online optical power detection circuit with calibrable accuracy comprises an MCU chip and an optical power detection circuit; the input end of the optical power detection circuit is connected to a receiving optical fiber seat, and the output end is connected to a DI interface of the MCU chip.

[0007] It also includes an optical power calibration circuit; the optical power calibration circuit includes multiple, the circuit structure of the multiple optical power calibration circuits is the same, the control ends of the multiple optical power calibration circuits are connected to the DO interface of the MCU chip, and the feedback ends of the multiple optical power calibration circuits are connected to the DI interface of the MCU chip.

[0008] The number of optical power calibration circuits is 2 n(n is a positive integer), and its circuit structure includes a fusible circuit structure. During calibration, the MCU chip performs the optical power calibration function, uses the standard light source as the optical signal input of the optical power detection circuit, and forms a binary calibration coefficient by controlling the fusible circuit in the optical power calibration circuit to open, so as to realize the solidification of the optical power calibration coefficient corresponding to the receiving fiber seat. The MCU chip program directly calls 2 n The optical power is calibrated by using a binary calibration coefficient of an optical power calibration circuit to realize an online optical power detection function with calibrable accuracy.

[0009] Furthermore, the optical power calibration circuit includes a pull-up resistor, an anti-reverse diode, a fuse, a current limiting resistor and a photoelectric switch. The upper end of the pull-up resistor is connected to the power supply Vcc, the lower end is connected to the anode of the anti-reverse diode and the DI interface of the MCU chip, the cathode of the anti-reverse diode is connected to the right end of the fuse, and the left end of the fuse is connected to the ground potential; the cathode of the anti-reverse diode is connected to the upper end of the current limiting resistor, the lower end of the current limiting resistor is connected to the right end of the photoelectric switch, the left end of the photoelectric switch is connected to the power supply Vcc, and the control end of the photoelectric switch is connected to the DO interface of the MCU chip.

[0010] Furthermore, a calibration button is included, which is connected between the power supply Vcc and the photoelectric switch of the optical power calibration circuit.

[0011] Furthermore, the upper end of the calibration button is connected to the power supply Vcc, and the lower end is also connected to the DI interface of the MCU chip. The lower end of the calibration button is also connected to one end of the calibration function detection resistor R10, and the other end of the detection resistor R10 is grounded.

[0012] Furthermore, the optical power detection circuit includes a receiving optical fiber seat, a sampling resistor R1, a filter capacitor C1 and an AD chip.

[0013] Furthermore, it also includes a status indication LED, which is connected to the DO interface of the MCU chip.

[0014] The online detection method of the online optical power detection circuit with calibrable accuracy comprises the following steps:

[0015] 1) A standard light source provides an optical signal with a fixed optical power and sends it to the receiving fiber optic holder. The receiving fiber optic holder outputs a received signal strength indicator signal as a current signal. After being sampled and filtered by the sampling resistor R1 and the filter capacitor C1, it is sent from the AD chip to the MCU chip via the DI interface. The MCU obtains an uncalibrated optical power signal.

[0016] 2) Since the optical power of the standard light source is known, the MCU chip compares the actual received optical power signal with the standard optical power signal to form the coefficient that needs to be calibrated. The coefficient is divided into 2n levels and expressed in binary.

[0017] 3) Before the operator presses the calibration button, the status indicator LED is off. After pressing the calibration button, the power supply Vcc is sent to the left end of the photoelectric switch of each optical power calibration circuit through the closed calibration button, and the calibration button signal input terminal of the MCU chip changes from low to high. After the MCU chip detects that this input terminal is set high, it starts the calibration process and controls the status indicator LED to flash, indicating that calibration is in progress.

[0018] 4) Based on the generated binary data, multiple optical power calibration circuits are controlled to be blown. Each binary bit corresponds to an optical power calibration circuit. The optical power calibration circuit corresponding to the binary data bit set to "1" is controlled to be blown as follows:

[0019] The MCU chip first controls the photoelectric switch to turn on, so that the power supply Vcc passes through the calibration button, photoelectric switch, and current-limiting resistor to supply power to the fuse to make it melt; after the fuse blows, the MCU chip detects that its corresponding DI interface signal is high, at this time the MCU chip controls the photoelectric switch to turn off.

[0020] 5) After the self-calibration process is completed, the MCU chip control status indicator LED turns to a steady state, indicating that the optical power calibration is completed;

[0021] 6) After the operator releases the calibration button, the calibration button signal input terminal of the MCU chip is set to low. After the MCU chip detects that this input terminal is set to low, the control status indicator LED becomes long off;

[0022] At this time, the calibration button is disconnected, the entire calibration process is completed, and the calibration coefficient corresponding to the receiving fiber optic seat is solidified. When the circuit is connected to the optical fiber communication signal again, the solidified calibration coefficient can be directly called, which realizes the online optical power detection function with calibrable accuracy.

[0023] Furthermore, the fusing current of the fuse does not exceed 0.2A, the current controlled by the current-limiting resistor is 2-3 times the fusing current of the fuse, and cannot exceed the output current upper limit of the Vcc power supply.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) Through the calibration process of the present invention, the calibration coefficient corresponding to the receiving optical fiber seat can be solidified. When the circuit is connected to the optical fiber communication signal again, the solidified calibration coefficient can be directly called, that is, the online optical power detection function with calibrated accuracy is realized. In engineering applications, this online optical power detection circuit with calibrated accuracy can provide a higher-precision detection function, which can improve the credibility of the detection data and provide more rigorous criteria for determining whether the detected board is normal and whether it should be processed during maintenance, better meeting the needs of engineering applications;

[0026] 2) Multiple sets of calibration circuits, each connected to a DI port and a DO port of the MCU chip, and setting the fixed accuracy calibration coefficient by controlling the fuse to open;

[0027] 3) The calibration button can provide both a calibration start signal and a fuse to cut out the power supply. After the button is cut out, it can prevent the solidified circuit from being rewritten.

[0028] 4) The calibration coefficient is multi-digit, but the number of digits can be expanded or reduced and can be set as needed;

[0029] 5) The added calibrated circuit does not affect the original optical power detection hardware path. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of an online optical power detection circuit with calibrable accuracy according to the present invention. DETAILED DESCRIPTION

[0031] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0032] like Figure 1 As shown, an online optical power detection circuit with calibrable accuracy includes an MCU chip and an optical power detection circuit; the input end of the optical power detection circuit is connected to the receiving optical fiber seat, and the output end is connected to the DI interface of the MCU chip;

[0033] It also includes an optical power calibration circuit; the optical power calibration circuit includes multiple, the circuit structure of the multiple optical power calibration circuits is the same, the control ends of the multiple optical power calibration circuits are connected to the DO interface of the MCU chip, and the feedback ends of the multiple optical power calibration circuits are connected to the DI interface of the MCU chip.

[0034] The number of optical power calibration circuits is 2 n(n is a positive integer), and its circuit structure includes a fusible circuit structure. During calibration, the MCU chip performs the optical power calibration function, uses the standard light source as the optical signal input of the optical power detection circuit, and forms a binary calibration coefficient by controlling the fusible circuit in the optical power calibration circuit to open, so as to realize the solidification of the optical power calibration coefficient corresponding to the receiving fiber seat. The MCU chip program directly calls 2 n The optical power is calibrated by using a binary calibration coefficient of an optical power calibration circuit to realize an online optical power detection function with calibrable accuracy.

[0035] The optical power calibration circuit includes a pull-up resistor, an anti-reverse diode, a fuse, a current-limiting resistor and a photoelectric switch. The upper end of the pull-up resistor is connected to a power supply Vcc, the lower end is connected to the anode of the anti-reverse diode and connected to the DI interface of the MCU chip, the cathode of the anti-reverse diode is connected to the right end of the fuse, and the left end of the fuse is connected to the ground potential; the cathode of the anti-reverse diode is connected to the upper end of the current-limiting resistor, the lower end of the current-limiting resistor is connected to the right end of the photoelectric switch, the left end of the photoelectric switch is connected to the power supply Vcc, and the control end of the photoelectric switch is connected to the DO interface of the MCU chip.

[0036] It also includes a calibration button, which is connected between the power supply Vcc and the photoelectric switch of the optical power calibration circuit.

[0037] The upper end of the calibration button is connected to the power supply Vcc, and the lower end is also connected to the DI interface of the MCU chip. The lower end of the calibration button is also connected to one end of the calibration function detection resistor R10, and the other end of the detection resistor R10 is grounded.

[0038] The optical power detection circuit includes a receiving fiber optic seat, a sampling resistor R1, a filter capacitor C1 and an AD chip. The communication signal of the receiving fiber optic seat is connected to the DI interface of the MCU chip. The signal of the receiving fiber optic seat is also sampled by the AD chip and connected to another DI interface of the MCU chip. The sampling resistor R1 and the filter capacitor C1 are connected between the sampling end and the ground end.

[0039] It also includes a status indication LED, which is connected to the DO interface of the MCU chip.

[0040] The principle behind this solution is that the calibrated circuit uses a standard light source as the calibration signal input. After receiving the optical power value reported by the AD chip, the MCU compares it with the labeled data to determine a binary calibration coefficient. When the calibration button is pressed, the MCU controls LED1 to flash and turns on the photoelectric switches corresponding to the DI ports to be set to 1, disconnecting the corresponding fuses. After the calibration process is complete, the MCU controls LED1 to illuminate steadily, indicating the completion of calibration. When the calibration button is released, the set DI signal serves as the fixed optical power calibration coefficient for the receiving fiber optic connector.

[0041] The present invention provides an online optical power detection circuit with calibrable accuracy. Without affecting basic communication signal transmission and basic optical power detection functions, the circuit uses a standard light source as the optical signal input. Upon pressing a calibration button, the MCU chip can perform an optical power calibration function and solidify the optical power calibration coefficient corresponding to the receiving fiber holder by controlling the corresponding fuse to open. The MCU chip program can directly call this binary calibration coefficient to calibrate the optical power, thereby achieving an online optical power detection function with calibrable accuracy.

[0042] The online detection method of the online optical power detection circuit with calibrable accuracy comprises the following steps:

[0043] 1) A standard light source provides an optical signal with a fixed optical power and sends it to the receiving fiber optic holder. The receiving fiber optic holder outputs a received signal strength indicator signal as a current signal. After being sampled and filtered by the sampling resistor R1 and the filter capacitor C1, it is sent from the AD chip to the MCU chip via the DI interface. The MCU obtains an uncalibrated optical power signal.

[0044] 2) Since the optical power of the standard light source is known, the MCU chip compares the actual received optical power signal with the standard optical power signal to form a coefficient that needs to be calibrated. The coefficient is divided into 2 n File, expressed in binary;

[0045] 3) Before the operator presses the calibration button, the status indicator LED is off. After pressing the calibration button, the power supply Vcc is sent to the left end of the photoelectric switch of each optical power calibration circuit through the closed calibration button, and the calibration button signal input terminal of the MCU chip changes from low to high. After the MCU chip detects that this input terminal is set high, it starts the calibration process and controls the status indicator LED to flash, indicating that calibration is in progress.

[0046] 4) Based on the generated binary data, multiple optical power calibration circuits are controlled to be blown. Each binary bit corresponds to an optical power calibration circuit. The optical power calibration circuit corresponding to the binary data bit set to "1" is controlled to be blown as follows:

[0047] The MCU chip first controls the photoelectric switch to turn on, so that the power supply Vcc passes through the calibration button, photoelectric switch, and current-limiting resistor to supply power to the fuse to make it melt; after the fuse blows, the MCU chip detects that its corresponding DI interface signal is high, at this time the MCU chip controls the photoelectric switch to turn off.

[0048] 5) After the self-calibration process is completed, the MCU chip control status indicator LED turns to a steady state, indicating that the optical power calibration is completed;

[0049] 6) After the operator releases the calibration button, the calibration button signal input terminal of the MCU chip is set to low. After the MCU chip detects that this input terminal is set to low, the control status indicator LED becomes long off;

[0050] At this time, the calibration button is disconnected, the entire calibration process is completed, and the calibration coefficient corresponding to the receiving fiber optic seat is solidified. When the circuit is connected to the optical fiber communication signal again, the solidified calibration coefficient can be directly called, which realizes the online optical power detection function with calibrable accuracy.

[0051] The breaking current of the fuse does not exceed 0.2A. The current controlled by the current limiting resistor is 2-3 times the breaking current of the fuse and cannot exceed the output current upper limit of the Vcc power supply. Specific embodiments

[0053] by Figure 1 Taking the embodiment of FIG1 as an example, to improve the accuracy of optical power detection, this solution adds a calibrable circuit to the basic optical power detection circuit, including four sets of optical power calibration circuits. The first pull-up resistor R2, the first anti-reverse diode D1, the first fuse F1, the first current-limiting resistor R6, and the first photoelectric switch S1 form the first calibration circuit; the second pull-up resistor R3, the second anti-reverse diode D2, the second fuse F2, the second current-limiting resistor R7, and the second photoelectric switch S2 form the second calibration circuit; the third pull-up resistor R4, the third anti-reverse diode D3, the third fuse F3, the third current-limiting resistor R8, and the third photoelectric switch S3 form the third calibration circuit; and the fourth pull-up resistor R5, the fourth anti-reverse diode D4, the fourth fuse F4, the fourth current-limiting resistor R9, and the fourth photoelectric switch S4 form the fourth calibration circuit. The first, second, third and fourth calibration circuits are all powered by Vcc, and report status information to the MCU chip via DI1, DI2, DI3 and DI4 respectively, and are controlled by the MCU chip to blow the corresponding fuse via DO1, DO2, DO3 and DO4 respectively.

[0054] The receiving fiber optic seat can receive conventional fiber optic communication signals and can also receive DC light signals emitted by standard light sources. The communication signal output by the receiving fiber optic seat is sent to the MCU chip via the DI7 interface; the received signal strength indication signal output by the receiving fiber optic seat is a current signal. After being sampled and filtered by the sampling resistor R1 and the filter capacitor C1, it is sent to the MCU chip by the AD chip via the DI6 interface.

[0055] Taking the first calibration circuit as an example, the upper end of the first pull-up resistor R2 is connected to Vcc, and the lower end is connected to the anode of the first anti-reverse diode D1 and to the DI1 interface of the MCU chip. The cathode of the first anti-reverse diode D1 is connected to the right end of the first fuse F1, and the left end of the first fuse F1 is connected to ground. The cathode of the first anti-reverse diode D1 is connected to the upper end of the first current-limiting resistor R6, the lower end of the first current-limiting resistor R6 is connected to the right end of the first photoelectric switch S1, the left end of the first photoelectric switch S1 is connected to the lower end of the calibration button, the upper end of the calibration button is connected to Vcc, the left end of the first photoelectric switch S1 is also connected to the DI5 interface of the MCU chip, and is connected to the calibration function detection resistor R10. The connection method of the second, third, and fourth calibration circuits is the same as that of the first calibration circuit.

[0056] The detection method of the circuit of this embodiment is: when an online optical power detection circuit with calibrable accuracy is normally connected to a standard light source and both are powered normally, the calibration button can be pressed to automatically complete the optical power accuracy calibration by the online optical power detection circuit with calibrable accuracy. The specific work flow is as follows.

[0057] 1) A standard light source provides an optical signal with a fixed optical power and sends it to the receiving fiber optic socket. The receiving fiber optic socket outputs a received signal strength indicator signal as a current signal. After sampling and filtering by sampling resistor R1 and filter capacitor C1, it is sent from the AD chip to the MCU chip via the DI6 interface. The MCU obtains an uncalibrated optical power signal.

[0058] 2) Since the optical power of the standard light source is known, the MCU chip compares the actual received optical power signal with the standard optical power signal to form the coefficient that needs to be calibrated. This coefficient can be divided into 16 levels (binary combinations of 4 calibration circuits). The following example uses the selected coefficient of 0101.

[0059] 3) Before the operator presses the calibration button, the status indicator LED1 is off. After pressing the calibration button, Vcc sends power to the left ends of the first photoelectric switch S1, the second photoelectric switch S2, the third photoelectric switch S3, and the fourth photoelectric switch S4 through the closed calibration button, and changes DI5 from low to high. After the MCU chip detects that DI5 is set high, it starts the calibration process and controls LED1 to flash, indicating that calibration is in progress.

[0060] 4) Taking the selected coefficient 0101 as an example, the MCU chip first controls the second photoelectric switch S2 to conduct, allowing Vcc to pass through the calibration button, the second photoelectric switch S2, and the second current-limiting resistor R7 to power the second fuse F2. When the value is generally selected, the fuse's melting current does not exceed 0.2A. The current controlled by the current-limiting resistor is generally 2-3 times the fuse's melting current and cannot exceed the output current upper limit of the Vcc power supply. After the second fuse F2 is blown, the MCU chip can detect that the DI2 signal is set high. At this time, the MCU chip controls the second photoelectric switch S2 to turn off and controls the fourth fuse F4 to conduct. Vcc passes through the calibration button, the fourth photoelectric switch S4, and the fourth current-limiting resistor R9 to power the fourth fuse F4. After the fourth fuse F4 is blown, the MCU chip can detect that the DI4 signal is set high. At this time, the MCU chip controls the fourth photoelectric switch S4 to turn off.

[0061] 5) After the self-calibration process is completed, the MCU chip controls LED1 to become constantly on, indicating that the optical power calibration is complete.

[0062] 6) After the operator releases the calibration button, DI5 is set to low. After the MCU chip detects that DI5 is set to low, it controls LED1 to become long off.

[0063] At this point, the calibration button is disconnected, the entire calibration process is complete, and the calibration coefficients corresponding to the receiving fiber optic connector are fixed. When the circuit is reconnected to the optical fiber communication signal, the four-bit fixed calibration coefficients can be directly called, thus achieving online optical power detection with calibrated accuracy. In engineering applications, this online optical power detection circuit with calibrated accuracy can provide higher-precision detection functions, improve the reliability of detection data, and provide more rigorous criteria for determining whether the detected board is normal and whether to handle it during maintenance, better meeting the needs of engineering applications.

[0064] The above embodiments are implemented under the premise of the technical solution of the present invention, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the above embodiments. The methods used in the above embodiments are conventional methods unless otherwise specified.

Claims

1. An online optical power detection circuit with calibrable accuracy, characterized in that: It includes an MCU chip and an optical power detection circuit; the input end of the optical power detection circuit is connected to the receiving optical fiber seat, and the output end is connected to the DI interface of the MCU chip; It also includes an optical power calibration circuit; the optical power calibration circuit includes multiple, multiple optical power calibration circuits have the same circuit structure, the control ends of the multiple optical power calibration circuits are connected to the DO interface of the MCU chip, and the feedback ends of the multiple optical power calibration circuits are connected to the DI interface of the MCU chip; The number of the optical power calibration circuits is 2 n Where n is a positive integer, its circuit structure includes a fusible circuit structure. During calibration, the MCU chip performs the optical power calibration function, uses the standard light source as the optical signal input of the optical power detection circuit, and forms a binary calibration coefficient by controlling the fusible circuit in the optical power calibration circuit to open, so as to realize the solidification of the optical power calibration coefficient corresponding to the receiving fiber seat. The MCU chip program directly calls 2 n The optical power is calibrated by using a binary calibration coefficient of an optical power calibration circuit to realize an online optical power detection function with calibrable accuracy.

2. The online optical power detection circuit with calibrable accuracy according to claim 1, characterized in that: The optical power calibration circuit includes a pull-up resistor, an anti-reverse diode, a fuse, a current-limiting resistor and a photoelectric switch. The upper end of the pull-up resistor is connected to a power supply Vcc, the lower end is connected to the anode of the anti-reverse diode and connected to the DI interface of the MCU chip, the cathode of the anti-reverse diode is connected to the right end of the fuse, and the left end of the fuse is connected to the ground potential; the cathode of the anti-reverse diode is connected to the upper end of the current-limiting resistor, the lower end of the current-limiting resistor is connected to the right end of the photoelectric switch, the left end of the photoelectric switch is connected to the power supply Vcc, and the control end of the photoelectric switch is connected to the DO interface of the MCU chip.

3. The online optical power detection circuit with calibrable accuracy according to claim 2, characterized in that: The device also includes a calibration button, which is connected between a power supply Vcc and a photoelectric switch of the optical power calibration circuit.

4. The online optical power detection circuit with calibrable accuracy according to claim 3, characterized in that: The upper end of the calibration button is connected to the power supply Vcc, and the lower end is also connected to the DI interface of the MCU chip. The lower end of the calibration button is also connected to one end of the calibration function detection resistor R10, and the other end of the detection resistor R10 is grounded.

5. The online optical power detection circuit with calibrable accuracy according to claim 4, characterized in that: The optical power detection circuit includes a sampling resistor R1, a filter capacitor C1 and an AD chip.

6. The online optical power detection circuit with calibrable accuracy according to claim 1, characterized in that: It also includes a status indication LED, which is connected to the DO interface of the MCU chip.

7. The online detection method of the online optical power detection circuit with calibrable accuracy according to claim 5, characterized in that: The steps include: 1) A standard light source provides an optical signal with a fixed optical power and sends it to the receiving fiber optic holder. The receiving fiber optic holder outputs a received signal strength indicator signal as a current signal. After being sampled and filtered by the sampling resistor R1 and the filter capacitor C1, it is sent from the AD chip to the MCU chip via the DI interface. The MCU obtains an uncalibrated optical power signal. 2) Since the optical power of the standard light source is known, the MCU chip compares the actual received optical power signal with the standard optical power signal to form a coefficient that needs to be calibrated. The coefficient is divided into 2 n File, expressed in binary; 3) Before the operator presses the calibration button, the status indicator LED is off. After pressing the calibration button, the power supply Vcc is sent to the left end of the photoelectric switch of each optical power calibration circuit through the closed calibration button, and the calibration button signal input terminal of the MCU chip changes from low to high. After the MCU chip detects that this input terminal is set high, it starts the calibration process and controls the status indicator LED to flash, indicating that calibration is in progress. 4) Based on the generated binary data, multiple optical power calibration circuits are controlled to be blown. Each binary bit corresponds to an optical power calibration circuit. The corresponding optical power calibration circuits with "1" in the binary data bit are controlled to be blown as follows: The MCU chip first controls the photoelectric switch to turn on, so that the power supply Vcc passes through the calibration button, photoelectric switch, and current-limiting resistor to supply power to the fuse, causing it to blow. After the fuse blows, the MCU chip detects that the corresponding DI interface signal is high, at which point the MCU chip controls the photoelectric switch to turn off. 5) After the above steps are completed, the MCU chip control status indicator LED turns to a steady state, indicating that the optical power calibration is complete; 6) After the operator releases the calibration button, the calibration button signal input terminal of the MCU chip is set to low. After the MCU chip detects that this input terminal is set to low, the control status indicator LED becomes long off; At this time, the calibration button is disconnected, the entire calibration process is completed, and the calibration coefficient corresponding to the receiving fiber optic seat is solidified. When the online optical power detection circuit with calibrable accuracy is connected to the optical fiber communication signal again, the solidified calibration coefficient is directly called, thus realizing the online optical power detection function with calibrable accuracy.

8. The online detection method of an online optical power detection circuit with calibrable accuracy according to claim 7, characterized in that: The breaking current of the fuse does not exceed 0.2A. The current controlled by the current limiting resistor is 2-3 times the breaking current of the fuse and cannot exceed the output current upper limit of the Vcc power supply.

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