Bus adapter and EMC test system

Abstract

The utility model belongs to the EMC detection technology, and particularly relates to a bus adapter and an EMC test system, and the bus adapter comprises a control unit and an optical conversion unit. The control unit and the light conversion unit are connected through an optical fiber; according to the bus adapter, the light conversion unit is additionally arranged on the basis of the design of a traditional bus adapter, and the light conversion unit is connected with the control unit through the optical fiber; the remote setting of the control unit can be realized by using the optical fiber, so that the influence of electromagnetic radiation of the control unit on the test of the equipment to be tested when the bus adapter is used as auxiliary test equipment can be greatly reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of EMC testing, and particularly relates to a bus adapter and an EMC testing system. Background Art

[0002] Generally, before being put on the market, electronic products need to pass FCC, CE or 3C certifications according to different sales regions. The most basic and common test among these certifications is the EMC test. The EMC test is mainly divided into two parts: First, the device should be able to work normally in a certain electromagnetic environment, that is, the device should have a certain electromagnetic sensitivity (EMS); Second, the electromagnetic interference generated by the device itself should not have too much impact on other electronic products, that is, electromagnetic interference (EMI).

[0003] In fields such as the automotive industry, aviation industry, industrial control, and safety protection, many electronic products communicate based on the CAN bus interface. In the EMC test, the bus adapter is one of the auxiliary test devices. When these products are undergoing EMC tests, they usually need to be connected to the bus adapter through a PC device and then interact through the CAN bus.

[0004] The processor part in the bus adapter will generate electromagnetic radiation into the space, thus having a negative impact on the test of the device under test.

[0005] Currently, the common way to deal with this problem is usually to increase the length of the CAN bus cable to increase the distance between the bus adapter and the device under test, which can, to a certain extent, reduce the impact of electromagnetic radiation on the test of the device under test. However, with the increasing CAN speed nowadays, the maximum length that the cable can support drops sharply.

[0006] Therefore, solving the technical problem that the processor part in the bus adapter has a negative impact on the test of the device under test due to its own electromagnetic radiation is an urgent technical problem to be solved in this field. Summary of the Utility Model

[0007] In order to solve the technical problems mentioned in the background art, the utility model provides a bus adapter and an EMC testing system.

[0008] The utility model provides a bus adapter, including: a control unit and an optical conversion unit; and the control unit and the optical conversion unit are connected through an optical fiber.

[0009] Further, the optical conversion unit includes:

[0010] a bus transceiver; and

[0011] The first optical conversion module is used to convert the electrical signal output by the bus transceiver into an optical signal and send it out through an optical fiber, and is also used to receive the optical signal from the control unit and convert the optical signal into an electrical signal to the bus transceiver.

[0012] Furthermore, it further includes: a protection circuit module; the bus transceiver is connected to the device under test through the protection circuit module.

[0013] Furthermore, the control unit includes:

[0014] A processor module, which is communicatively connected to a PC device; and

[0015] A second optical conversion module is used to convert the electrical signal output by the processor module into an optical signal and send it out through an optical fiber, and is also used to receive the optical signal from the optical conversion unit and convert the optical signal into an electrical signal to the processor module.

[0016] Furthermore, it further includes: an impedance matching reservation circuit module; the bus signal output by the processor module is output to the second optical conversion module after being debugged by the impedance matching reservation circuit module.

[0017] On the other hand, the present invention also provides a bus adapter, including:

[0018] An optical conversion unit, in which a first optical conversion module is provided;

[0019] A control unit, in which a second optical conversion module is provided;

[0020] Wherein, the first optical conversion module and the second optical conversion module are communicatively connected through an optical fiber.

[0021] Furthermore, the optical conversion unit includes a bus transceiver;

[0022] The first optical conversion module is used to convert the electrical signal output by the bus transceiver into an optical signal and send it out through an optical fiber, and is also used to receive the optical signal from the control unit and convert the optical signal into an electrical signal to the bus transceiver.

[0023] Furthermore, the control unit includes a processor module;

[0024] The second optical conversion module is used to convert the electrical signal output by the processor module into an optical signal and send it out through an optical fiber, and is also used to receive the optical signal from the optical conversion unit and convert the optical signal into an electrical signal to the processor module.

[0025] In the third aspect, the present invention also provides an EMC test system, including:

[0026] A PC device, a device under test, and the bus adapter as described above;

[0027] The PC device and the device to be tested are communicatively connected through the bus adapter.

[0028] In a fourth aspect, the present utility model further provides an EMC test system, including:

[0029] The bus adapter as described above;

[0030] The bus adapter is adapted to communicatively connect two devices.

[0031] The beneficial effect of the present utility model is that, on the basis of the traditional bus adapter design, the present bus adapter adds an optical conversion unit, and the optical conversion unit and the control unit are connected by an optical fiber in the middle; by using the optical fiber, remote setting of the control unit can be realized, thereby greatly reducing the influence of the electromagnetic radiation of the control unit on the test of the device to be tested when the bus adapter is used as an auxiliary test device. Description of the Drawings

[0032] The present utility model will be further described below in conjunction with the drawings and embodiments.

[0033] Figure 1 is the principle block diagram of the bus adapter provided by some embodiments;

[0034] Figure 2 is the circuit diagram of the bus transceiver provided by some embodiments;

[0035] Figure 3 is the circuit diagram of the first optical conversion module provided by some embodiments;

[0036] Figure 4 is the circuit diagram of the protection circuit module provided by some embodiments;

[0037] Figure 5(a) is a partial circuit diagram of the processor module provided by some embodiments;

[0038] Figure 5(b) is another partial circuit diagram of the processor module provided by some embodiments;

[0039] Figure 6 is the circuit diagram of the second optical conversion module provided by some embodiments;

[0040] Figure 7 is the circuit diagram of the impedance matching reserved circuit module provided by some embodiments;

[0041] Figure 8 is the principle block diagram of the EMC test system provided by some embodiments. Detailed Embodiments

[0042] The present utility model will now be further described in detail with reference to the accompanying drawings. These drawings are all simplified schematic diagrams, only illustrating the basic structure of the present utility model in a schematic manner, and thus only showing the components related to the present utility model.

[0043] Glossary of Terms

[0044] EMC (Electro Magnetic Compatibility) testing: Electromagnetic compatibility testing

[0045] CAN (Controller Area Network): Controller Area Network

[0046] CANFD (CAN with Flexible Data rate): Controller Area Network with Flexible Data Rate

[0047] TXD (Transmit Data) pin: Data transmission pin

[0048] RXD (Receive Data) pin: Data reception pin

[0049] CANH (Controller Area Network High) pin: CAN bus high-level differential signal line pin

[0050] CANL (Controller Area Network Low) pin: CAN bus low-level differential signal line pin

[0051] PC (Personal Computer) device: Personal computer

[0052] As Figure 1 shown, the embodiment of the present disclosure provides a bus adapter, including: a control unit and an optical conversion unit; and the control unit and the optical conversion unit are connected by an optical fiber.

[0053] Specifically, the bus adapter of this embodiment adds an optical conversion unit on the basis of the traditional bus adapter design. The optical conversion unit and the control unit are connected by an optical fiber in the middle; when the device under test is undergoing EMC testing, the optical conversion unit can be connected to the device under test through the CAN bus, and the control unit can be placed far away from the device under test to reduce the impact of the electromagnetic radiation of the control unit as an auxiliary test device on the testing of the device under test.

[0054] In this embodiment, since the control unit of the bus adapter is far from the device under test, its electromagnetic radiation can be almost negligible for the EMC test of the device under test. Thus, the electromagnetic radiation generated when the bus adapter is used as an auxiliary test device for EMC testing is greatly reduced, and the reliability of the EMC test is improved.

[0055] In some embodiments, the optical conversion unit includes: a bus transceiver connected to the device under test through a protection circuit module; and a first optical conversion module configured to convert the electrical signal output by the bus transceiver into an optical signal and transmit it through an optical fiber, and further configured to receive the optical signal from the control unit and convert the optical signal into an electrical signal to the bus transceiver.

[0056] Specifically, in this embodiment, multiple bus signals correspond to multiple optical conversion units, and each bus signal corresponds to an optical conversion unit one by one. In this embodiment, a CAN signal is taken as an example.

[0057] Specifically, as Figure 2 shown, the model of the bus transceiver is TJA1042T / 3 transceiver. As Figure 3 shown, the model of the first optical conversion module is GT-WT532-F3-I optical module; the TXD pin of the TJA1042T / 3 transceiver is connected to the RD(OUT) pin of the first optical conversion module, and the RXD pin of the TJA1042T / 3 transceiver is connected to the TD(IN) pin of the first optical conversion module; and as Figure 4 shown, the CANH pin and CANL pin of the TJA1042T / 3 transceiver serve as the input terminals of the protection circuit module, and the bus data is output to the device under test through the protection circuit module.

[0058] In some embodiments, the control unit includes: a processor module communicatively connected to an external PC device; and a second optical conversion module configured to convert the electrical signal output by the processor module into an optical signal and transmit it through an optical fiber, and further configured to receive the optical signal from the optical conversion unit and convert the optical signal into an electrical signal to the processor module.

[0059] Specifically, as shown in FIGS. 5(a) and 5(b), the model of the processor module can be STM32H723VET6 microcontroller; as Figure 6 shown, the model of the second optical conversion module is GT-WT532-F3-I optical module; as Figure 7 shown, the bus signal FDCAN1_TXD output by the processor module is output to the second optical conversion module as the CAN1_TXD signal after being debugged by the impedance matching reservation circuit module. The second optical conversion module converts it and outputs the CAN1_RXD signal, and the CAN1_RXD signal is transmitted through an optical fiber to the first optical conversion module.

[0060] For common fiber optic transceivers, the delay in converting electrical signals to optical signals and then back to electrical signals is usually less than 100 ns. The propagation delay of optical signals in each meter of optical fiber is about 5 ns. For the currently commonly used CAN and CANFD protocols, when operating at the highest communication rate (arbitration segment baud rate of 1 M), the maximum tolerable delay is 200 ns. At this time, the maximum acceptable length of the optical fiber is about 20 M. If the communication rate is reduced, the length of the optical fiber can be longer, reaching up to hundreds of meters.

[0061] In summary, the bus adapter of this embodiment uses optical fiber to isolate the device under test and the control unit. Coupled with the fact that the optical fiber can be set to a relatively long length, it can also greatly reduce the impact of the electromagnetic radiation of the control unit on the test of the device under test.

[0062] This embodiment also provides a bus adapter, including: an optical conversion unit with a first optical conversion module disposed therein; a control unit with a second optical conversion module disposed therein; wherein, the first optical conversion module and the second optical conversion module are connected and communicate through an optical fiber.

[0063] In some embodiments, the optical conversion unit includes a bus transceiver; the first optical conversion module is used to convert the electrical signal output by the bus transceiver into an optical signal and then send it out through the optical fiber, and is also used to receive the optical signal from the control unit and convert the optical signal into an electrical signal to the bus transceiver.

[0064] In some embodiments, the control unit includes a processor module; the second optical conversion module is used to convert the electrical signal output by the processor module into an optical signal and then send it out through the optical fiber, and is also used to receive the optical signal from the optical conversion unit and convert the optical signal into an electrical signal to the processor module.

[0065] As Figure 8 shown, this embodiment also provides an EMC test system, including: a PC device, a device under test, and the bus adapter as described above; the PC device and the device under test are communicatively connected through the bus adapter.

[0066] This embodiment also provides an EMC test system, including: the bus adapter as described above; the bus adapter is adapted to communicatively connect two devices.

[0067] Specifically, this embodiment makes improvements to the bus adapter. For the PC device and the device under test, both belong to the prior art, and this embodiment does not make any improvements to the specific circuits or structures of the PC device and the device under test.

[0068] Inspired by the above-described ideal embodiments of the present utility model, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this utility model. The technical scope of this utility model is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A bus adapter, characterized in that: include: A control unit and a light conversion unit; as well as The control unit and the optical conversion unit are connected via an optical fiber; The light conversion unit comprises: Bus transceiver; as well as The first optical conversion module is used to convert the electrical signal output by the bus transceiver into an optical signal and then send it out through the optical fiber. It is also used to receive the optical signal from the control unit and convert the optical signal into an electrical signal to the bus transceiver.

2. The bus adapter according to claim 1, characterized in that: Also includes: Protection circuit module; The bus transceiver is connected to the device under test through the protection circuit module.

3. The bus adapter according to claim 1, characterized in that: The control unit comprises: A processor module, communicating with a PC device; and The second optical conversion module is used to convert the electrical signal output by the processor module into an optical signal and then send it out through the optical fiber. It is also used to receive the optical signal from the optical conversion unit and convert the optical signal into an electrical signal to the processor module.

4. The bus adapter according to claim 3, characterized in that: Also includes: Impedance matching reserved circuit module; The bus signal output by the processor module is output to the second optical conversion module after being debugged by the impedance matching reserved circuit module.

5. A bus adapter, characterized in that: include: A light conversion unit, in which a first light conversion module is disposed; A control unit, in which a second light conversion module is disposed; Wherein, the first optical conversion module communicates with the second optical conversion module via an optical fiber connection; The optical conversion unit includes a bus transceiver; The first optical conversion module is used to convert the electrical signal output by the bus transceiver into an optical signal and then send it out through the optical fiber. It is also used to receive the optical signal from the control unit and convert the optical signal into an electrical signal to the bus transceiver.

6. The bus adapter according to claim 5, characterized in that: The control unit includes a processor module; The second optical conversion module is used to convert the electrical signal output by the processor module into an optical signal and then send it out through the optical fiber. It is also used to receive the optical signal from the optical conversion unit and convert the optical signal into an electrical signal to the processor module.

7. An EMC test system, characterized in that: include: A PC device, a device under test, and a bus adapter as described in any one of claims 1 to 4 or 5 to 6; The PC device and the device under test are communicatively connected via the bus adapter.

8. An EMC test system, characterized in that: include: A bus adapter as claimed in any one of claims 1 to 4 or 5 to 6; The bus adapter is suitable for connecting two devices for communication.

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