FTTR debugging and testing system

Abstract

The invention relates to the technical field of optical fiber communication, in particular to an FTTR modulation and test system which comprises an optical port modulation and test subsystem and a flow test subsystem. The optical modem test subsystem comprises a multi-channel optical modem test assembly and an extinction ratio tester; the multi-channel optical modem test assembly comprises an optical comprehensive test instrument, a one-to-two optical splitter, a clock data recovery instrument, an optical oscilloscope, a bit error tester and an upper computer. The N to-be-tested optical modems and the extinction ratio tester are electrically connected to the upper computer; the flow test subsystem comprises a network tester, OLT optical access equipment and a plurality of groups of flow test loops arranged between the network tester and the OLT optical access equipment, and each flow test loop comprises a first optical power meter, a first optical attenuator, an optical modem to be tested, a second optical power meter, a second optical attenuator and an accompanying optical modem. According to the invention, the production cost of the optical port debugging and testing process can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of optical fiber communication, and in particular to an FTTR modulation and testing system. Background Art

[0002] With the rapid development of the access network market and technology, PON terminal products (including FTTR products) are continuously launched. However, due to the discreteness of optical devices, each PON terminal product must debug and test the optical port related parameters during the production stage to meet the performance index requirements. Therefore, optical port debugging and testing are necessary basic production processes. At present, various manufacturers generally adopt the method of separate debugging and testing during the optical modem testing process to avoid product production indicators exceeding the range due to line loss or equipment deviation, and there is no independent test station to intercept and cause defective products to flow into the next station. As a result, the investment of equipment resources is large, and the labor and maintenance costs are also high. Summary of the invention

[0003] The object of the present invention is to provide a FTTR debugging and testing system, which can reduce the production cost of the optical port debugging and testing process.

[0004] In order to achieve the above-mentioned object, a FTTR modulation test system is provided, including an optical port modulation test subsystem, wherein the optical port modulation test subsystem includes a multi-channel optical modem modulation test assembly, and the multi-channel optical modem modulation test assembly includes an optical comprehensive tester, an optical oscilloscope and a host computer; the optical port modulation test subsystem also includes an extinction ratio tester; N optical modems to be tested and the extinction ratio tester in the multi-channel optical modem modulation test assembly are electrically connected to the host computer and the optical comprehensive tester;

[0005] Also includes flow test subsystem:

[0006] The flow test subsystem includes: a network tester, an OLT optical access device and several groups of flow test loops arranged between the network tester and the OLT optical access device, the flow test loop includes a first optical power meter, a first optical attenuator, an optical modem to be tested, a second optical power meter, a second optical attenuator and a companion optical modem; the network tester and the OLT optical access device are connected through optical fiber, the network tester is connected to the first optical attenuator and the ONU port of the optical modem to be tested in sequence through the optical fiber, the ONU port of the optical modem to be tested emits light and is output to the first optical power meter through a splitter; the optical modem to be tested is connected to the network tester through a network cable; the companion optical modem is connected to the network tester through a network cable, and is connected to the second optical attenuator and the OLT port of the optical modem to be tested in sequence through optical fiber, the OLT port of the optical modem to be tested emits light and is output to the second optical power meter through a splitter.

[0007] Furthermore, the optical port adjustment test subsystem includes the following modules:

[0008] Extinction ratio debugging module: used to control the light emission of the optical modem to be tested and output it to the extinction ratio tester through the optical comprehensive tester, cancel the test value of the optical ratio tester by reading, and adjust the extinction ratio of the optical modem to be tested to the target value;

[0009] It is also used to control the light emission of the optical modem to be tested and output it to the optical oscilloscope through the optical comprehensive tester. By reading the test value of the optical oscilloscope, it can be judged whether the extinction ratio is debugged in place.

[0010] Furthermore, the flow test subsystem includes the following modules:

[0011] Packet loss detection module: used to enable the network tester to send a signal flow to the OLT optical access device, so that the OLT optical access device forwards the signal flow to the ONU port of the optical modem to be tested through the first optical attenuator, wherein a part of the signal flow is directly transmitted back to the network tester by the optical modem to be tested through the network cable, so that the network tester can test whether there is packet loss by comparing the sent and received signal flows; the other part of the signal flow passes through the OLT port of the optical modem to be tested, and is transmitted back to the network tester through the second optical attenuator and the companion optical modem, so that the network tester can test whether there is packet loss by comparing the sent and received signal flows.

[0012] Furthermore, the flow test subsystem includes the following modules:

[0013] The first test module: used for the TX optical power test and DDMI monitoring test of the ONU port of the optical modem to be tested. The ONU port of the optical modem to be tested emits light through the splitter to the first optical power meter. The first optical power meter is used to test whether its actual optical power is qualified. At the same time, its DDMI monitoring value is read, and the DDMI monitoring value is compared with the actual optical power meter reading. If the difference meets the set range, it is qualified. If not, it is unqualified and returns to the optical port adjustment test subsystem for re-adjustment.

[0014] Furthermore, the flow test subsystem includes the following modules:

[0015] The second test module: used for the RX DDMI test of the ONU port of the optical modem to be tested. The first optical attenuator is adjusted to make the optical power output by the OLT optical access device to the ONU port of the optical modem to be tested be at different optical powers. The optical modem to be tested is subjected to a DDMI test at different optical powers. The DDMI monitoring values ​​corresponding to different optical powers are read and the difference between the two is calculated. If the difference meets the set range, it is qualified. If not, it is unqualified.

[0016] Furthermore, the flow test subsystem includes the following modules:

[0017] The third test module: used for the TX optical power test and DDMI monitoring test of the OLT port of the optical modem to be tested. The OLT port of the optical modem to be tested emits light through the splitter to the second optical power meter. The second optical power meter is used to test whether its actual optical power is qualified. At the same time, its DDMI monitoring value is read and compared with the actual optical power meter reading. If the difference meets the set range, it is qualified. If not, it is unqualified and returns to the optical port adjustment test system for re-adjustment.

[0018] Furthermore, the flow test subsystem includes the following modules:

[0019] The fourth test module: used for the RX DDMI test of the OLT port of the optical modem to be tested, adjust the second optical attenuator so that the optical power output from the companion optical modem to the OLT port of the optical modem to be tested is at different optical powers, perform DDMI test on the optical modem to be tested at different optical powers, read the DDMI monitoring values ​​corresponding to different optical powers, and calculate the difference between the two. If the difference meets the set range, it is qualified, otherwise it is unqualified.

[0020] Principles and advantages:

[0021] 1. The debugging and testing subsystem of this solution has added an extinction ratio tester and an optical oscilloscope. The extinction ratio tester is used to debug the DUT extinction ratio parameters, and the optical oscilloscope is used to test the DUT extinction ratio parameters, avoiding the deviation of debugging results caused by using the same equipment (the probability of instability or deviation of the optical oscilloscope and the extinction ratio tester at the same time is relatively low).

[0022] 2. If the test fiber jumper is dirty, or the optical power meter and optical attenuator in the optical tester are unstable or deviated, the integrated test and adjustment solution cannot effectively intercept the DUT with unqualified indicators. This solution puts the TX / RX optical power test into the flow test subsystem (the optical port test system and the flow test use different fiber jumpers and test equipment, and the probability of problems is relatively low), avoiding instability or deviation, improving efficiency and reducing costs.

[0023] 3. The traffic test subsystem of this solution uses the FTTR sub-gateway as a companion test device, and can perform traffic tests on the ONU and OLT ends of the FTTR main gateway (optical modem to be tested) at the same time, avoiding the cost increase caused by separate traffic tests.

[0024] 4. In the traffic test subsystem of this solution, programmable optical attenuators and optical power meters are added to the ONU and OLT ends of the optical modem to be tested, and a splitter is used to connect the optical attenuator, optical power meter and the optical modem to be tested. It can be compatible with all optical products and perform upstream and downstream tests at the same time, thereby reducing the production cost of the optical port debugging and testing process of the optical modem product. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is the logic block diagram of the hardware structure of the optical port test subsystem;

[0026] Figure 2 This is the logic block diagram of the hardware structure of the flow test subsystem. DETAILED DESCRIPTION

[0027] The following is further described in detail through specific implementation methods:

[0028] Example

[0029] A FTTR modulation test system, basically as follows Figure 1 , Figure 2 As shown, it includes a server, an optical port tuning test subsystem and a flow test subsystem, and the server is communicatively connected to the optical port tuning test subsystem and the flow test subsystem.

[0030] like Figure 1 As shown, the hardware structure of the optical port modulation test subsystem includes: a multi-channel optical modem modulation test component and an extinction ratio tester; the multi-channel optical modem modulation test component includes an optical comprehensive tester, a 1-to-2 optical splitter, a clock data recovery instrument, an optical oscilloscope, a bit error tester and an independent host computer (computer); N optical modems to be tested in the multi-channel optical modem modulation test component (such as Figure 2 The ONU type optical modem) and the extinction ratio tester are electrically connected to the host computer and the optical comprehensive tester; the host computer (computer) is connected to the server for communication. The multi-channel optical modem adjustment test component has been disclosed in the prior art, as follows:

[0031] It includes N optical modems to be tested, 1-to-2 optical splitters, optical comprehensive tester (N-channel optical switch, 1-to-N optical splitter, N 1-to-2 optical splitters, N wavelength division multiplexers WDM, optical power meter and optical attenuator that can provide N optical channels respectively), clock data recovery instrument CDR, optical oscilloscope, bit error tester and host computer;

[0032] The output end of the bit error meter is connected to the input end of the 1-to-N optical splitter, the N optical channel output ends of the 1-to-N optical splitter are respectively connected to the N optical channel input ends of the optical attenuator, the N optical channel output ends of the optical attenuator are respectively connected to the input ends of the N wavelength division multiplexers, and the common ends of the N wavelength division multiplexers are respectively connected to the signal input ends of the N optical modems to be tested;

[0033] The signal output ends of N optical modems to be tested are respectively connected to the common ends of N wavelength division multiplexers, the output ends of N wavelength division multiplexers are respectively connected to the common input ports of N 1-to-2 optical splitters, one of the optical channel output ends of the N 1-to-2 optical splitters is respectively connected to the N optical channel input ends of the optical power meter, the other optical channel output end of the N 1-to-2 optical splitters is respectively connected to the N optical channel input ends of the N-channel optical switch, the output end of the N-channel optical switch is connected to the common input end of the last 1-to-2 optical splitter, one of the optical channel output ends of the 1-to-2 optical splitter is connected to the first input end of the optical oscilloscope, the other optical channel output end of the 1-to-2 optical splitter is connected to the input end of the clock data recovery instrument, and the RF port of the clock data recovery instrument is connected to the second input end of the optical oscilloscope;

[0034] The bit error meter, optical comprehensive tester, optical oscilloscope, extinction ratio tester and N optical modems to be tested are all connected to the host computer signal.

[0035] like Figure 2 As shown, the hardware structure of the traffic test subsystem includes: an independent host computer, a network tester, an OLT optical access device, and several groups of traffic test loops set between the network tester and the OLT optical access device; the host computer is communicatively connected to the server, and the network tester and the OLT optical access device are communicatively connected.

[0036] Each flow test loop includes a first optical power meter (optical power meter 1), a first optical attenuator (optical attenuator 1), an optical modem to be tested (DUT), a second optical power meter (optical power meter 2), a second optical attenuator (optical attenuator 2) and a companion optical modem (companion ONU sub-optical modem); a network tester, an OLT optical access device, and the first optical power meter (optical power meter 1), the first optical attenuator (optical attenuator 1), the second optical power meter (optical power meter 2), and the second optical attenuator (optical attenuator 2) of several groups of flow test loops are all electrically connected to a host computer.

[0037] The network tester is connected to the OLT optical access device through an optical fiber, and the network tester is connected to the first optical attenuator and the ONU port of the optical modem to be tested in sequence through the optical fiber, and the ONU port of the optical modem to be tested emits light through a splitter to output to the first optical power meter; the optical modem to be tested is connected to the network tester through a network cable; the companion optical modem is connected to the network tester through a network cable, and is connected to the second optical attenuator and the OLT port of the optical modem to be tested in sequence through the optical fiber, and the OLT port of the optical modem to be tested emits light through a splitter to output to the second optical power meter. In this embodiment, the flow test loop is provided with 16 groups, and the specific number can be selected according to the needs.

[0038] The first optical power meter is used to test the TX optical power of the ONU optical port of the optical modem to be tested, and the first optical attenuator is used to test the RX monitoring optical power of the ONU optical port of the optical modem to be tested.

[0039] The ONU optical port of the companion optical modem is connected to the OLT optical port of the optical modem to be tested, and the network port of the companion optical modem is connected to the network tester to test the downlink link traffic of the OLT optical port of the optical modem to be tested, and to test the TX optical power of the OLT optical port of the optical modem to be tested by reading the RX monitoring optical power of the ONU of the companion optical modem.

[0040] The OLT optical port of the optical modem to be tested is respectively connected to the second optical power meter and the second optical attenuator through an optical splitter.

[0041] In the software composition of the optical port adjustment test subsystem, the host computer is preferably a computer, which includes the following modules:

[0042] Extinction ratio debugging module: used to control the light emission of the optical modem to be tested and output it to the extinction ratio tester through the optical comprehensive tester, cancel the test value of the optical ratio tester by reading, and adjust the extinction ratio of the optical modem to be tested to the target value; also used to control the light emission of the optical modem to be tested and output it to the optical oscilloscope through the optical comprehensive tester, read the test value of the optical oscilloscope, and judge whether the extinction ratio is debugged in place.

[0043] The computer in the optical port adjustment and testing subsystem also includes one or more combinations of the following modules:

[0044] DUT RX LOS debugging module: The modulated signal from the bit error tester is output to the optical modem to be tested through the optical attenuator in the optical comprehensive tester. The optical attenuator is adjusted to attenuate to the LOS alarm value for debugging the DUT LOS alarm; the optical attenuator is adjusted to attenuate to the LOS de-alarm value for debugging the DUT LOS de-alarm. After the LOS debugging is completed, increase and decrease the attenuation to test the LOS alarm and de-alarm respectively to determine whether the debugging is in place. DUT receiving end (RX) APD debugging and sensitivity test module: Adjust the attenuator in the optical comprehensive tester so that the optical power output to the DUT is at the APD debugging power value, debug the APD voltage, and ensure that the APD debugging is successful. Adjust the optical attenuator so that the optical power output to the DUT is at the DUT sensitivity power value. At this time, test the DUT sensitivity to determine whether the APD is debugged in place. DUT RX overload test module: Adjust the attenuator so that the optical power output to the DUT is at the overload power test point. At this time, test the DUT overload. DUT RX DDMI calibration module: adjust the optical attenuator so that the optical power output to the DUT is at different optical power calibration points (usually 3 power points, such as -25, -18, and -10dbm), and perform DDMI calibration on the DUT at different optical powers. DUT transmitter (TX) optical power debugging module: control the DUT to output the light to the optical power meter in the optical comprehensive tester, and adjust the DUT power to the target value by reading the test value of the optical power meter. DUT TX eye diagram test module: control the DUT to output the light to the optical oscilloscope through the optical comprehensive tester, and judge whether the DUT eye diagram is qualified by reading the relevant eye diagram indicators of the optical oscilloscope (such as mask margin, cross point, rise / fall time, etc.). DUT TX optical power calibration module: control the DUT to output the light to the optical power meter in the optical comprehensive tester, and calibrate its DDMI monitoring value by reading the test value of the optical power meter.

[0045] In the software composition of the flow test subsystem, its corresponding host computer includes a packet loss detection module, a first test module, a second test module, a third test module and a fourth test module: the host computer calls the corresponding module according to the test requirements.

[0046] Packet loss detection module: used to enable the network tester to send a signal flow to the OLT optical access device, so that the OLT optical access device forwards the signal flow to the ONU port of the optical modem to be tested through the first optical attenuator, wherein a part of the signal flow is directly transmitted back to the network tester by the optical modem to be tested through the network cable, so that the network tester can test whether there is packet loss by comparing the sent and received signal flows; the other part of the signal flow passes through the OLT port of the optical modem to be tested, and is transmitted back to the network tester through the second optical attenuator and the companion optical modem, so that the network tester can test whether there is packet loss by comparing the sent and received signal flows.

[0047] The first test module: used for the TX optical power test and DDMI monitoring test of the ONU port of the optical modem to be tested. The ONU port of the optical modem to be tested emits light through the splitter to the first optical power meter. The first optical power meter is used to test whether its actual optical power is qualified. At the same time, its DDMI monitoring value is read, and the DDMI monitoring value is compared with the actual optical power meter reading. If the difference meets the set range, it is qualified. If not, it is unqualified and returns to the optical port adjustment test subsystem for re-adjustment.

[0048] The second test module: used for the RX DDMI test of the ONU port of the optical modem to be tested. The first optical attenuator is adjusted to make the optical power output by the OLT optical access device to the ONU port of the optical modem to be tested be at different optical powers (generally 3 power points, such as -25, -18, and -10dbm). The optical modem to be tested is subjected to DDMI test at different optical powers. The DDMI monitoring values ​​corresponding to different optical powers are read, and the difference between the two is calculated. If the difference meets the set range, it is qualified. If not, it is unqualified (for example, when the DUT ONU receiving optical power is set to -25dbm through the attenuator, the difference between its DDMI monitoring value and -25 is read. If the difference meets the set range, it is qualified. If not, it is unqualified).

[0049] The third test module: used for the TX optical power test and DDMI monitoring test of the OLT port of the optical modem to be tested. The OLT port of the optical modem to be tested emits light through the splitter to the second optical power meter. The second optical power meter is used to test whether its actual optical power is qualified. At the same time, its DDMI monitoring value is read and compared with the actual optical power meter reading. If the difference meets the set range, it is qualified. If not, it is unqualified and returns to the optical port adjustment test system for re-adjustment.

[0050] The fourth test module: used for the RX DDMI test of the OLT port of the optical modem to be tested, adjust the second optical attenuator so that the optical power output by the companion optical modem to the OLT port of the optical modem to be tested is at different optical powers (generally 3 power points, such as -25, -18, and -10dbm), perform DDMI test on the optical modem to be tested at different optical powers, read the DDMI monitoring values ​​corresponding to different optical powers, and calculate the difference between the two. If the difference meets the set range, it is qualified, otherwise it is unqualified (for example, when the DUTONU receiving optical power is set to -25dbm through the attenuator, read the difference between its DDMI monitoring value and -25. If the difference meets the set range, it is qualified, otherwise it is unqualified).

[0051] The debugging and testing subsystem of this solution adds both an extinction ratio tester and an optical oscilloscope. The extinction ratio tester is used to debug the DUT extinction ratio parameters, and the optical oscilloscope is used to test the DUT extinction ratio parameters, thus avoiding the deviation of debugging results caused by using the same device.

[0052] If the test fiber jumper is dirty, or the optical power meter and optical attenuator in the optical tester are unstable or deviated, the integrated debugging and testing solution cannot effectively intercept the DUT with unqualified indicators. This solution puts the TX / RX optical power test in the traffic test subsystem, avoiding instability or deviation, improving efficiency and reducing costs.

[0053] The traffic test subsystem of this solution uses the FTTR sub-gateway (i.e., the ONU-type optical modem to be tested) as a companion test device, and can perform traffic tests on the ONU and OLT ends of the FTTR main gateway (i.e., the OLT-type optical modem to be tested) at the same time, avoiding the cost increase caused by separate traffic tests.

[0054] In the traffic test subsystem of this solution, programmable optical attenuators and optical power meters are added to the ONU and OLT ends of the optical modem to be tested, and a splitter is used to connect the optical attenuator, optical power meter and the optical modem to be tested. It can be compatible with all optical products and perform upstream and downstream tests at the same time, thereby reducing the production cost of the optical port debugging and testing process of the optical modem product.

[0055] The above is only an embodiment of the present invention. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. An FTTR modulation test system, comprising an optical port modulation test subsystem, wherein the optical port modulation test subsystem comprises a multi-channel optical modem modulation test component, wherein the multi-channel optical modem modulation test component comprises an optical comprehensive tester, an optical oscilloscope and a host computer; characterized in that: The optical port adjustment test subsystem also includes an extinction ratio tester; the N optical modems to be tested and the extinction ratio tester in the multi-channel optical modem adjustment test assembly are electrically connected to the host computer and the optical comprehensive tester; Also includes flow test subsystem: The flow test subsystem includes: a network tester, an OLT optical access device and several groups of flow test loops arranged between the network tester and the OLT optical access device, the flow test loop includes a first optical power meter, a first optical attenuator, an optical modem to be tested, a second optical power meter, a second optical attenuator and a companion optical modem; the network tester and the OLT optical access device are connected through optical fiber, the network tester is connected to the first optical attenuator and the ONU port of the optical modem to be tested in sequence through the optical fiber, the ONU port of the optical modem to be tested emits light and is output to the first optical power meter through a splitter; the optical modem to be tested is connected to the network tester through a network cable; the companion optical modem is connected to the network tester through a network cable, and is connected to the second optical attenuator and the OLT port of the optical modem to be tested in sequence through optical fiber, the OLT port of the optical modem to be tested emits light and is output to the second optical power meter through a splitter.

2. The FTTR tuning test system according to claim 1, characterized in that: The optical port adjustment test subsystem includes the following modules: Extinction ratio debugging module: used to control the light emission of the optical modem to be tested and output it to the extinction ratio tester through the optical comprehensive tester, cancel the test value of the optical ratio tester by reading, and adjust the extinction ratio of the optical modem to be tested to the target value; It is also used to control the light emission of the optical modem to be tested and output it to the optical oscilloscope through the optical comprehensive tester. By reading the test value of the optical oscilloscope, it can be judged whether the extinction ratio is debugged in place.

3. The FTTR tuning test system according to claim 2, characterized in that: The flow test subsystem includes the following modules: Packet loss detection module: used to enable the network tester to send a signal flow to the OLT optical access device, so that the OLT optical access device forwards the signal flow to the ONU port of the optical modem to be tested through the first optical attenuator, wherein a part of the signal flow is directly transmitted back to the network tester by the optical modem to be tested through the network cable, so that the network tester can test whether there is packet loss by comparing the sent and received signal flows; the other part of the signal flow passes through the OLT port of the optical modem to be tested, and is transmitted back to the network tester through the second optical attenuator and the companion optical modem, so that the network tester can test whether there is packet loss by comparing the sent and received signal flows.

4. The FTTR tuning test system according to claim 3, characterized in that: The flow test subsystem includes the following modules: The first test module: used for the TX optical power test and DDMI monitoring test of the ONU port of the optical modem to be tested. The ONU port of the optical modem to be tested emits light through the splitter to the first optical power meter. The first optical power meter is used to test whether its actual optical power is qualified. At the same time, its DDMI monitoring value is read, and the DDMI monitoring value is compared with the actual optical power meter reading. If the difference meets the set range, it is qualified. If not, it is unqualified and returns to the optical port adjustment test subsystem for re-adjustment.

5. The FTTR tuning test system according to claim 4, characterized in that: The flow test subsystem includes the following modules: The second test module: used for the RX DDMI test of the ONU port of the optical modem to be tested. The first optical attenuator is adjusted to make the optical power output by the OLT optical access device to the ONU port of the optical modem to be tested be at different optical powers. The optical modem to be tested is subjected to a DDMI test at different optical powers. The DDMI monitoring values ​​corresponding to different optical powers are read and the difference between the two is calculated. If the difference meets the set range, it is qualified. If not, it is unqualified.

6. The FTTR tuning test system according to claim 5, characterized in that: The flow test subsystem includes the following modules: The third test module: used for the TX optical power test and DDMI monitoring test of the OLT port of the optical modem to be tested. The OLT port of the optical modem to be tested emits light through the splitter to the second optical power meter. The second optical power meter is used to test whether its actual optical power is qualified. At the same time, its DDMI monitoring value is read and compared with the actual optical power meter reading. If the difference meets the set range, it is qualified. If not, it is unqualified and returns to the optical port adjustment test system for re-adjustment.

7. The FTTR tuning test system according to claim 6, characterized in that: The flow test subsystem includes the following modules: The fourth test module: used for the RX DDMI test of the OLT port of the optical modem to be tested, adjust the second optical attenuator so that the optical power output from the companion optical modem to the OLT port of the optical modem to be tested is at different optical powers, perform DDMI test on the optical modem to be tested at different optical powers, read the DDMI monitoring values ​​corresponding to different optical powers, and calculate the difference between the two. If the difference meets the set range, it is qualified, otherwise it is unqualified.

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