Automatic test system and test method for QSFP28 interface optical module

Abstract

The invention discloses an automatic test system for a QSFP28 interface optical module, which comprises a computer, a QSFP28 test board, a standard optical module, an optical module to be tested, an optical attenuator, an optical power meter, a bit error tester, an oscilloscope and an optical splitter, the standard optical module provides an optical signal and transmits the optical signal to a receiving end of the to-be-tested optical module, and the to-be-tested optical module receives the instruction and the data transmitted by the QSFP28 test board and correspondingly modifies a register of the to-be-tested optical module according to the corresponding instruction and the data. According to the automatic test system and test method for the QSFP28 interface optical module, operation of a measuring instrument and writing of register parameters of the optical module are controlled through the system, automatic test of the optical module to be tested is achieved, the workload of workers is greatly reduced, the consistency of the performance of the optical module is ensured, and the production efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of automated testing of optical modules, and in particular to an automated testing system and a testing method for a QSFP28 interface optical module. Background Art

[0002] With the continuous development of AI and the Internet, the data traffic of network communications is also growing. As the requirements for communication latency and data volume continue to increase, optical communications are also slowly developing. As an important component of the optical communication system, the optical module is mainly used for the conversion of photoelectric signals. The electrical signal is converted into an optical signal at the transmitting end of the optical module. The optical signal is transmitted to the receiving end of the optical module through the optical fiber and then converted into an electrical signal.

[0003] As an important module in the optical communication network, the performance of the optical module directly affects the data integrity and communication quality during the communication process. Therefore, each optical module needs to be tested and calibrated according to the parameters of the optical module before leaving the factory to ensure that each optical module is reliable.

[0004] At present, traditional optical module testing solutions are all measured manually by workers. Since the test requires the use of instruments such as bit error meters, optical attenuators, oscilloscopes, and optical power meters, the steps are complicated for factory operators, the error rate is high, and the operation of the test instruments and the evaluation of performance indicators are greatly affected by human factors, making it difficult to ensure the consistency of product performance. At the same time, the test relies on manual operation by workers, and the production efficiency is also low. Summary of the invention

[0005] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is that the operation of the test instrument and the evaluation of the performance index in the existing test method are greatly affected by human factors, and it is difficult to ensure the consistency of product performance. At the same time, since a variety of measuring instruments are manually operated and set by workers, the production efficiency is low. The present invention provides an automated testing system and a testing method for a QSFP28 interface optical module, which controls the operation of the measuring instrument and the writing of the register parameters of the optical module to be tested, realizes the automated testing of the optical module to be tested, greatly reduces the workload of workers, ensures the consistency of the performance of the optical module to be tested, and improves production efficiency.

[0006] To achieve the above-mentioned purpose, the present invention provides an automated test system for QSFP28 interface optical modules, comprising a computer, a QSFP28 test board, a standard optical module, an optical module to be tested, an optical attenuator, an optical power meter, a bit error meter, an oscilloscope and an optical splitter, wherein the computer runs a host computer program to receive user instructions, and sends the corresponding instructions and data to the optical module to be tested through the QSFP28 test board; the standard optical module provides an optical signal and transmits the optical signal to the receiving end of the optical module to be tested; the optical module to be tested receives the instructions and data sent by the QSFP28 test board, and tests itself according to the corresponding instructions and data. The register is modified accordingly; the receiving end of the optical attenuator is connected to the standard optical module, and the output end of the optical attenuator performs expected attenuation on the optical signal power according to user requirements and outputs the attenuated optical signal. The attenuated optical signal is connected to the optical power meter through the optical splitter and to the receiving end of the optical module to be tested; the optical power meter measures the output optical power of the optical module to be tested and the output optical power of the standard optical module in real time, and transmits them to the host computer program of the computer; the bit error meter is used as a test symbol generator to test the bit error performance of the optical module to be tested during data transmission; the oscilloscope measures the optical eye diagram of the output optical signal of the optical module to be tested.

[0007] Furthermore, the host computer program includes a DDM calibration module, a coding module for the register of the optical module to be measured, a coding verification module for the register of the optical module to be measured and a firmware burning module for the optical module to be measured; the host computer program sequentially runs the firmware burning module for the optical module to be measured, the DDM calibration module, the coding module for the register of the optical module to be measured and the coding verification module for the register of the optical module to be measured.

[0008] Furthermore, the QSFP28 test board receives instructions sent by the host computer, and performs corresponding operations according to the instructions to read and write the register information of the optical module to be tested.

[0009] Furthermore, the interfaces of the QSFP28 test board include a USB interface, a QSFP28 interface, and an SMA interface, wherein the QSFP28 test board is connected to and communicates with the computer via the USB interface; the QSFP28 test board is connected to the optical module to be tested via the QSFP28 interface and communicates with the optical module to be tested; the QSFP28 test board is connected to the bit error tester via the SMA interface to transmit electrical signals.

[0010] Furthermore, the standard optical module outputs standard optical power, and the output optical signal of the standard optical module is connected to the input end of the optical module to be tested after passing through an optical attenuator, so as to be used for receiving calibration of the optical module to be tested.

[0011] Furthermore, the optical power meter includes two units, one for measuring the output optical power of the standard optical module and finally used for the receiving calibration of the optical module to be tested, and the other for measuring the output optical power of the optical module to be tested and finally used for the transmitting calibration of the optical module to be tested.

[0012] Another preferred embodiment of the present invention provides a test method for an automated test system for a QSFP28 interface optical module, comprising the following steps:

[0013] Load relevant configuration files through the computer and initialize relevant parameters;

[0014] Check whether the optical module to be tested is connected to the QSFP28 test board;

[0015] Burn the firmware of the optical module to be tested;

[0016] Perform emission calibration and receiving calibration on the light module to be measured;

[0017] The computer sets the voltage reporting value of the optical module to be tested by reading the configuration file, and writes the corresponding parameters into the register of the optical module to be tested;

[0018] Record the current shell temperature value of the optical module to be measured, set and calibrate the temperature reporting value of the optical module to be measured according to the current shell temperature value of the optical module to be measured, and write the relevant parameters into the register of the optical module to be measured;

[0019] The relevant information is written into the register of the module to be tested through the register writing module of the optical module to be tested;

[0020] The code writing verification module is used to detect whether the information is correct through the register of the optical module to be tested.

[0021] Furthermore, the emission calibration is performed on the light module to be measured, specifically, the emission light power of the light module to be measured is calibrated, and then the eye diagram of the light module to be measured is checked.

[0022] Furthermore, the receiving calibration of the optical module to be measured is performed, specifically including first calibrating the receiving optical power of the optical module to be measured, then performing a receiving sensitivity test on the optical module to be measured, and then testing and calibrating the LOS Assert and LOSDeAssert values ​​of the optical module to be measured, and finally, testing and calibrating the IDark Assert and IDark DeAssert values ​​of the optical module to be measured.

[0023] Technical Effects

[0024] The present invention provides an automated testing system and testing method for QSFP28 interface optical modules, which are used for production debugging of optical modules to be tested and batch flashing of module firmware and registers. By using a computer host to control the operation of the measuring instrument and the writing of register parameters of the optical module to be tested, the automated testing of the optical module to be tested is realized, which greatly reduces the workload of workers, ensures the consistency of the performance of the optical module to be tested, and improves the production efficiency of the optical module to be tested.

[0025] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural diagram of an automated test system for QSFP28 interface optical modules according to a preferred embodiment of the present invention;

[0027] Figure 2 It is a flowchart of an optical module automated test system for an optical module with a QSFP28 interface according to a preferred embodiment of the present invention;

[0028] Figure 3 It is a flow chart of emission calibration during the automated testing of an optical module of an automated testing system for a QSFP28 interface optical module according to a preferred embodiment of the present invention;

[0029] Figure 4 The present invention is a flowchart of receiving calibration during an optical module automated test process of an automated test system for a QSFP28 interface optical module according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] In the following description, specific details such as specific internal procedures and techniques are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0032] like Figure 1As shown, the present invention provides an automated test system for a QSFP28 interface optical module, comprising: a computer, a QSFP28 test board, a standard optical module, an optical module to be tested, an optical attenuator, an optical power meter, a bit error meter, an oscilloscope, and an optical splitter. The computer runs a host program to receive user instructions, and sends the corresponding instructions and data to the optical module to be tested through the QSFP28 test board; the standard optical module provides an optical signal and transmits the optical signal to the receiving end of the optical module to be tested; the optical module to be tested receives the instructions and data sent by the QSFP28 test board, and modifies its own register accordingly according to the corresponding instructions and data; the receiving end of the optical attenuator is connected to the standard optical module, the output end of the optical attenuator performs expected attenuation on the optical signal power according to user requirements, and outputs the attenuated optical signal, the attenuated optical signal is connected to the optical power meter through the optical splitter, and is connected to the receiving end of the optical module to be tested; the optical power meter measures the output optical power of the optical module to be tested and the output optical power of the standard optical module in real time, and transmits them to the host program of the computer, and the host program in the computer reads the optical power value displayed in the optical power meter; the bit error meter is used as a test code generator to test the bit error performance of the optical module to be tested during data transmission; the oscilloscope measures the optical eye diagram of the optical signal output by the optical module to be tested.

[0033] Among them, the host computer program runs in the computer, and the host computer program is used to interact with the user, receive the instructions issued by the user, and perform corresponding operations according to the instructions, thereby controlling the work of the optical module to be tested, the optical attenuator, the optical power meter, the bit error meter, and the oscilloscope. The host computer program includes a DDM calibration module, a register code writing module for the optical module to be tested, a register code writing verification module for the optical module to be tested, and a firmware burning module for the optical module to be tested. The DDM calibration module is used to calibrate the reported values ​​of the temperature, voltage, bias current, transmitted optical power, and received optical power in the optical module; the register code writing module for the optical module to be tested is used to write information such as manufacturer information, module SN serial number, module working speed, and module DDM threshold into the register table in the optical module; the register code writing verification module for the optical module to be tested is used to verify whether the information written in the register of the optical module is correct; the firmware burning module for the optical module to be tested is used to burn the firmware of the optical module. The host computer program runs the firmware burning module for the optical module to be tested, the DDM calibration module, the register code writing module for the optical module to be tested, and the register code writing verification module for the optical module to be tested in sequence.

[0034] The QSFP28 test board is used to receive host computer instructions and perform corresponding operations according to the instructions, and is used to read and write the register information of the optical module to be tested. The QSFP28 test board contains three interfaces: USB interface, QSFP28 interface, and SMA interface. The USB interface is used to connect the computer to communicate with the host computer; the QSFP28 interface is used to connect the optical module to communicate with the optical module; the SMA interface is connected to the bit error meter for transmitting electrical signals. Among them, the computer is connected to the test board through the USB interface, and the computer can send corresponding instructions to the test board through the USB interface; there is a QSFP28 interface on the test board, and the optical module to be tested is inserted into the test board through the QSFP28 interface, which is used to power the optical module to be tested, forward the instructions sent by the computer to the optical module to be tested, and transmit the electrical signal converted by the optical module to be tested. The SMA interface is used to transmit electrical signals. The optical module to be tested will convert the optical signal into an electrical signal. What is transmitted by SMA is the electrical signal converted by the optical module to be tested and the test code element generated by the bit error meter. On the test board, the line connected to the SMA interface is connected to the QSFP28 interface.

[0035] The standard optical module is used to output standard optical power. The optical signal output by the standard optical module passes through the optical attenuator and then the optical splitter, and then is connected to the optical power meter and the receiving end of the optical module to be tested, which is used to test and calibrate the receiving end of the optical module to be tested.

[0036] The optical module to be tested is used as the debugged end to receive relevant instructions from the host computer, so as to report the relevant information of the module or modify the register content. The transmitting end of the optical module to be tested is connected to the optical power meter and oscilloscope to calibrate and debug the module's transmitted optical power, extinction ratio, etc. The receiving end of the optical module to be tested is connected to the transmitting end of the standard optical module to debug and calibrate the received optical power and sensitivity of the optical module to be tested. Among them, the relevant instructions of the host computer include reading or writing the contents of the register of the optical module to be tested.

[0037] There are two optical power meters, one for measuring the output optical power of the standard optical module and finally for the receiving calibration of the optical module to be tested, and the other for measuring the output optical power of the optical module to be tested and finally for the transmitting calibration of the optical module to be tested.

[0038] The optical attenuator is used to output the input optical signal after a certain attenuation. It is used in the calibration stage of the received optical power and sensitivity test of the optical module to be tested. The receiving end of the optical attenuator is connected to the output end of the standard optical module, and the optical signal output by the output end of the optical attenuator is the output optical signal of the standard optical module after a certain attenuation. The optical attenuator is connected to the computer through the USB interface. The host program in the computer sends instructions to the optical attenuator to control the specific attenuation amount of the optical attenuator. For example, the attenuation value can be configured to be 10dB. Then, when the input optical power of the optical attenuator is -1dB, the output optical power of the optical attenuator is -11dB.

[0039] The optical power meter is used to measure the optical signal power value. The measured optical power value can be used to measure and calibrate the received optical power and transmitted optical power of the optical module to be tested. The optical power value measured by the optical power meter will be sent to the computer through the USB port, and the host computer program in the computer will read the optical power value displayed in the optical power meter.

[0040] The bit error meter is used to generate test symbols to test the bit error performance of the optical module during operation. It can be used to test the receiving sensitivity of the optical module to be tested. The bit error meter can display the current bit error rate information, and the computer can obtain the information in the bit error meter through the USB interface.

[0041] The oscilloscope is used to display the optical eye diagram at the output end of the optical module to be tested. The eye diagram can be used to measure and calibrate parameters such as the extinction ratio and cross ratio of the optical module to be tested.

[0042] An optical splitter is used to decompose one optical signal into two optical signals.

[0043] like Figure 2 As shown, an embodiment of the present invention provides a method for testing an optical module based on an automated testing system for a QSFP28 interface optical module, comprising the following steps:

[0044] Step 1, the computer loads relevant configuration files and initializes relevant parameters;

[0045] Step 2: Check whether the optical module to be tested is connected to the QSFP28 test board;

[0046] Step 3, burning the firmware of the optical module to be tested;

[0047] Step 4: perform emission calibration of the optical module to be tested, including emission optical power calibration of the optical module to be tested and eye diagram verification of the optical module to be tested.

[0048] Step 5, perform receiving calibration of the optical module to be tested, including receiving optical power calibration of the optical module to be tested, receiving sensitivity test of the optical module to be tested, testing and calibrating LOS Assert and LOSDeAssert values ​​of the optical module to be tested, and testing and calibrating IDark Assert and IDark DeAssert values ​​of the optical module to be tested.

[0049] Step 6, the computer sets and calibrates the voltage reporting value of the optical module to be tested by reading the configuration file, and writes the corresponding parameters into the register of the optical module to be tested;

[0050] Step 7, recording the current temperature value of the housing of the optical module to be measured, setting and calibrating the temperature reporting value of the optical module to be measured according to the current temperature value of the housing of the optical module to be measured, and writing the corresponding parameters into the register of the optical module to be measured;

[0051] Step 8, write the device manufacturer information, SN serial number, DDM threshold and other information into the corresponding register of the optical module to be tested through the optical module register writing module to be tested;

[0052] Step 9: Check whether the information written in the above step 8 is correct by using the code writing verification module of the register of the optical module to be tested.

[0053] like Figure 3 As shown, the emission calibration flow chart of the optical module automated test process in the embodiment of the present invention includes the following steps:

[0054] Step 1: calibrate the optical power of the optical module to be tested. The optical signal emitted by the transmitting end of the optical module to be tested is connected to the optical power meter after passing through the optical splitter. The host computer reads the optical power values ​​displayed by the four channels in the optical power meter through the USB interface, calibrates the reported value of the optical power emitted by the optical module to be tested, and writes the corresponding parameters into the corresponding registers of the optical module to be tested.

[0055] Step 2, perform eye diagram calibration of the optical module to be tested. The optical signal emitted by the transmitting end of the optical module to be tested is connected to the oscilloscope after passing through the optical splitter. The computer reads the output optical eye diagram parameters of the optical module to be tested displayed on the oscilloscope through the USB interface, adjusts the corresponding parameters of the optical module to be tested, so that the extinction ratio, cross ratio, eye diagram margin and other parameters in the optical eye diagram meet the requirements, and writes the corresponding parameters into the register of the optical module to be tested.

[0056] like Figure 4 As shown, the calibration flow chart of receiving during the automated testing of the optical module in the embodiment of the present invention includes the following steps:

[0057] Step 1, calibrate the received optical power of the optical module to be tested. The optical signal output from the output end of the standard optical module passes through the optical attenuator and the optical splitter, and the two optical signals are respectively connected to the input end of the optical module to be tested and the optical power meter. Therefore, the optical power value at the input end of the optical module to be tested is the value displayed in the optical power meter. The host computer adjusts the attenuation value of the optical attenuator so that the optical power value at the input end of the optical module to be tested is two special calibration point values ​​(the optical power value displayed by the optical power meter should be the two special calibration point values ​​at this time). When the optical power value at the input end of the optical module to be tested is two special calibration point values, the host computer records the current reported received optical power value of the optical module to be tested. The host computer fits a straight line by calculating these two sets of data, obtains the slope and intercept values, and writes the calculated slope and intercept into the register of the optical module to be tested.

[0058] Step 2, perform a receiving sensitivity test of the optical module to be tested. The computer reads the bit error rate displayed in the bit error meter through the USB interface, and continuously adjusts the value of the optical attenuator to obtain the bit error rate under different received optical powers of the optical module to be tested, and fits the curve based on the received optical power and bit error rate of the optical module to be tested. According to the obtained curve, the optical power value at a specific bit error rate is calculated, and then the optical power value is the receiving sensitivity of the optical module. Next, the host computer adjusts the attenuation value of the optical attenuator so that the received optical power value of the optical module to be tested is the receiving sensitivity calculated above, and then runs for a period of time. The host computer reads the data in the bit error meter to detect whether there is a bit error. If there is no bit error, the sensitivity test passes.

[0059] Step 3, test and calibrate the LOS Assert and LOSDeAssert values ​​of the optical module to be tested. First, the host computer adjusts the attenuation value of the optical attenuator so that the optical power received by the optical module to be tested is the LOSDeAssert optical power value specified in the configuration file. The host computer records the parameters at this time and writes them into the register of the optical module to be tested. Next, the host computer adjusts the attenuation value of the optical attenuator so that the optical power received by the optical module to be tested is the LOS Assert optical power value specified in the configuration file. The host computer records the parameters at this time and writes them into the register of the optical module to be tested.

[0060] Step 4, test and calibrate the IDark Assert and IDark DeAssert values ​​of the optical module to be tested. First, the host computer adjusts the attenuation value of the optical attenuator so that the optical power received by the optical module to be tested is the IDark DeAssert optical power value specified in the configuration file. The host computer records the parameters at this time and writes them into the register of the optical module to be tested. Next, the host computer adjusts the attenuation value of the optical attenuator so that the optical power received by the optical module to be tested is the IDark Assert optical power value specified in the configuration file. The host computer records the parameters at this time and writes them into the register of the optical module to be tested.

[0061] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. An automated test system for QSFP28 interface optical modules, characterized in that: The invention comprises a computer, a QSFP28 test board, a standard optical module, an optical module to be tested, an optical attenuator, an optical power meter, a bit error meter, an oscilloscope and an optical splitter, wherein the computer runs a host computer program to receive user instructions, and sends corresponding instructions and data to the optical module to be tested through the QSFP28 test board; the standard optical module provides an optical signal and transmits the optical signal to the receiving end of the optical module to be tested; the optical module to be tested receives the instructions and data sent by the QSFP28 test board, and modifies its own register accordingly according to the corresponding instructions and data; the receiving end of the optical attenuator is connected to the optical module to be tested; The optical module to be tested is connected to the standard optical module, the output end of the optical attenuator performs expected attenuation on the optical signal power according to user requirements, and outputs the attenuated optical signal, the attenuated optical signal is connected to the optical power meter through the optical splitter, and is connected to the receiving end of the optical module to be tested; the optical power meter measures the output optical power of the optical module to be tested and the output optical power of the standard optical module in real time, and transmits them to the host computer program of the computer; the bit error meter is used as a test symbol generator to test the bit error performance of the optical module to be tested during data transmission; the oscilloscope measures the optical eye diagram of the optical signal output by the optical module to be tested.

2. An automated test system for QSFP28 interface optical modules as claimed in claim 1, characterized in that: The host computer program of the computer includes a DDM calibration module, a code writing module for the register of the optical module to be measured, a code writing verification module for the register of the optical module to be measured and a firmware burning module for the optical module to be measured; the host computer program sequentially runs the firmware burning module for the optical module to be measured, the DDM calibration module, the code writing module for the register of the optical module to be measured and the code writing verification module for the register of the optical module to be measured.

3. An automated test system for QSFP28 interface optical modules as claimed in claim 2, characterized in that: The QSFP28 test board receives the instruction sent by the host computer, performs corresponding operations according to the instruction, and reads and writes the register information of the optical module to be tested.

4. The automated test system for QSFP28 interface optical modules according to claim 3, characterized in that: The interfaces of the QSFP28 test board include a USB interface, a QSFP28 interface, and an SMA interface, wherein the QSFP28 test board is connected to and communicates with the computer via the USB interface; the QSFP28 test board is connected to the optical module to be tested via the QSFP28 interface and communicates with the optical module to be tested; the QSFP28 test board is connected to the bit error meter via the SMA interface to transmit electrical signals.

5. The automated test system for QSFP28 interface optical modules according to claim 1, characterized in that: The standard optical module outputs standard optical power, and the output optical signal of the standard optical module is connected to the input end of the optical module to be measured after passing through an optical attenuator, so as to be used for receiving calibration of the optical module to be measured.

6. The automated test system for QSFP28 interface optical modules according to claim 1, characterized in that: The optical power meter includes two units, one is used to measure the output optical power of the standard optical module and finally used for the receiving calibration of the optical module to be measured, and the other is used to measure the output optical power of the optical module to be measured and finally used for the transmitting calibration of the optical module to be measured.

7. A test method for an automated test system for a QSFP28 interface optical module according to any one of claims 1 to 6, characterized in that: The following steps are involved: Load relevant configuration files through the computer and initialize relevant parameters; Check whether the optical module to be tested is connected to the QSFP28 test board; Burn the firmware of the optical module to be tested; Perform emission calibration and receiving calibration on the light module to be measured; The computer sets the voltage reporting value of the optical module to be tested by reading the configuration file, and writes the corresponding parameters into the register of the optical module to be tested; Record the current shell temperature value of the optical module to be measured, set and calibrate the temperature reporting value of the optical module to be measured according to the current shell temperature value of the optical module to be measured, and write the relevant parameters into the register of the optical module to be measured; The relevant information is written into the register of the module to be tested through the register writing module of the optical module to be tested; The code writing verification module is used to detect whether the information is correct through the register of the optical module to be tested.

8. The automated testing method for a QSFP28 interface optical module according to claim 7, characterized in that: The emission calibration is performed on the optical module to be measured, specifically, the emission optical power of the optical module to be measured is calibrated, and then the eye diagram of the optical module to be measured is checked.

9. The automated testing method for a QSFP28 interface optical module according to claim 7, characterized in that: The receiving calibration of the optical module to be measured specifically includes first calibrating the receiving optical power of the optical module to be measured, then performing a receiving sensitivity test on the optical module to be measured, and then testing and calibrating the LOS Assert and LOSDeAssert values ​​of the optical module to be measured, and finally, testing and calibrating the IDark Assert and IDark DeAssert values ​​of the optical module to be measured.

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