Ethernet bus optoelectronic isolation system

Abstract

The utility model discloses an ethernet bus photoelectric isolation system, include: first ethernet photoelectric isolation module is used for with measured object connection, receives the ethernet signal of measured object, second ethernet photoelectric isolation module is used for with bus analyzer connection, receives the signal from first ethernet photoelectric isolation module and transmission to bus analyzer, bus signal optical fiber is used for connecting first ethernet photoelectric isolation module and second ethernet photoelectric isolation module, realizes the signal transmission of first ethernet photoelectric isolation module and second ethernet photoelectric isolation module. The utility model, correct transmission signal and to signal waveform carries out proper correction, guarantees the interference that comes through its transmission after ethernet signal can satisfy the limit value requirement of test standard.

Description

Technical Field

[0001] This utility model relates to the field of opto-isolation system technology, specifically an Ethernet bus opto-isolation system. Background Technology

[0002] With technological advancements, the proportion of electronic components in automobiles is increasing, and their designs are becoming more complex. Ethernet bus technology in automobiles coordinates the operation of various electronic components. As one of the most popular bus technologies among automakers, Ethernet bus technology covers almost all automotive products currently on the market. In addition to using traditional audio, video, antenna tower control signals, and turntable control signals, automotive electronic electromagnetic compatibility testing requires extensive signal monitoring of the product under test, necessitating the installation of various automotive bus opto-isolation systems, and at least an Ethernet bus opto-isolation system.

[0003] According to electromagnetic compatibility (EMC) testing requirements, the product should be in normal operating condition during testing. When the product under test needs to receive commands via an Ethernet bus to operate, an Ethernet signal opto-isolation system is essential. Ethernet signal waveforms are close to square waves and have abundant harmonics. During frequency domain measurements, if the Ethernet signal is passed directly into the system without any processing, the following problems may occur: Insufficient noise reduction of the output Ethernet bus signal leads to electromagnetic interference derived from the Ethernet bus signal exceeding background noise requirements. Excessive noise reduction of the output Ethernet bus signal results in a severe degradation of the Ethernet bus signal quality, which can cause packet loss and communication interruptions at high transmission rates. Utility Model Content

[0004] The purpose of this invention is to provide an Ethernet bus opto-isolation system to solve the problems in the prior art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: an Ethernet bus opto-isolation system, comprising: The first Ethernet opto-isolation module is used to connect to the device under test and receive the Ethernet signal from the device under test. The second Ethernet opto-isolation module is used to connect to the bus analyzer, receive signals from the first Ethernet opto-isolation module and transmit them to the bus analyzer. The bus signal fiber is used to connect the first Ethernet opto-isolation module and the second Ethernet opto-isolation module to realize signal transmission between the first Ethernet opto-isolation module and the second Ethernet opto-isolation module.

[0006] Preferably, the first Ethernet opto-isolation module is powered by a battery box, and the second Ethernet opto-isolation module is powered by a battery box or a power adapter.

[0007] Preferably, both the first Ethernet opto-isolation module and the second Ethernet opto-isolation module include an Ethernet switching chip, a common-mode filter, and a connector.

[0008] Preferably, the bus signal fiber is a multimode fiber optic cable.

[0009] Compared with the prior art, the beneficial effects of this utility model are: to correctly transmit signals and appropriately correct the signal waveform, ensuring that the interference caused by the Ethernet signal after transmission can meet the limit requirements of the test standard. Attached Figure Description

[0010] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is the circuit diagram of this utility model; Figure 2 This is a schematic diagram of the present invention; Figure 3 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely to represent selected embodiments of this utility model.

[0012] Please see Figure 1-3 In this embodiment of the present invention, an Ethernet bus opto-isolation system includes: The first Ethernet opto-isolation module is used to connect to the device under test and receive the Ethernet signal from the device under test. The second Ethernet opto-isolation module is used to connect to the bus analyzer, receive signals from the first Ethernet opto-isolation module and transmit them to the bus analyzer. The bus signal fiber is used to connect the first Ethernet opto-isolation module and the second Ethernet opto-isolation module to realize signal transmission between the first Ethernet opto-isolation module and the second Ethernet opto-isolation module.

[0013] Preferably, the first Ethernet opto-isolation module is powered by a battery box, and the second Ethernet opto-isolation module is powered by a battery box or a power adapter.

[0014] Preferably, both the first and second Ethernet opto-isolation modules include an Ethernet switching chip, a common-mode filter, and a connector. The MDIP (pin 4) and MDIN (pin 5) of the Ethernet switching chip are connected to pins 2 and 1 of the CMC1 (ACT1210G-800-2P-TL05), respectively. Pins 3 and 4 of the common-mode filter are connected to two 100nF capacitors, the other ends of which are connected to subsequent circuit nodes. A circuit consisting of a 1kΩ resistor, a 100kΩ resistor, and a 4.7nF capacitor is also connected to this circuit. The MDI_P and MDI_N pins of the connector are connected to the lines formed by the capacitors, resistors, and other components. Additionally, a circuit consisting of a 120Ω resistor and a 4.7nF capacitor is connected to the relevant nodes and grounded.

[0015] Preferably, the bus signal fiber is a multimode fiber optic cable.

[0016] The first Ethernet opto-isolation module is located in an anechoic chamber or shielded room, and the second Ethernet opto-isolation module is located in a remote control room. The two are connected across space via a bus signal optical fiber.

[0017] Connect the Ethernet to the DUT; connect the Ethernet module at the remote end via a multimode fiber optic cable; the module connected to the DUT must be battery powered; the remote module can be powered by a battery or an external power adapter.

[0018] When an opto-isolator is connected to the sample's Ethernet bus line, the signal quality degrades significantly or is interrupted, while it functions normally without the opto-isolator. The main reason is that during noise reduction, the LC circuits used respond differently to different frequencies, and some LC circuits can cause signal distortion in the transmitted data. When the frequency corresponding to the data transmission rate is below the frequency band that causes signal distortion in the LC circuit, signal transmission is generally guaranteed. However, once the transmission rate increases, the corresponding frequency rises, and signal distortion leads to communication interruptions. A well-designed bus opto-isolator system should correctly transmit signals and appropriately correct the signal waveform to ensure that the interference from the Ethernet signal transmitted through it meets the limits of the testing standards.

[0019] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An Ethernet bus opto-isolation system, characterized in that, include: The first Ethernet opto-isolation module is used to connect to the device under test and receive the Ethernet signal from the device under test. The second Ethernet opto-isolation module is used to connect to the bus analyzer, receive signals from the first Ethernet opto-isolation module and transmit them to the bus analyzer. The bus signal fiber is used to connect the first Ethernet opto-isolation module and the second Ethernet opto-isolation module to realize signal transmission between the first Ethernet opto-isolation module and the second Ethernet opto-isolation module.

2. The Ethernet bus opto-isolation system according to claim 1, characterized in that, The first Ethernet opto-isolation module is powered by a battery box, and the second Ethernet opto-isolation module is powered by a battery box or a power adapter.

3. The Ethernet bus opto-isolation system according to claim 1, characterized in that, Both the first Ethernet opto-isolation module and the second Ethernet opto-isolation module include an Ethernet switching chip, a common-mode filter, and a connector.

4. The Ethernet bus opto-isolation system according to claim 1, characterized in that, The bus signal fiber is a multimode fiber optic cable.

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