Radial target beam current signal monitoring system based on integrated data acquisition card

Abstract

The application discloses a radial target beam signal monitoring system based on an integrated data acquisition card, and has the characteristics that: a short-distance beam signal line is arranged at an accelerator site; a data acquisition card based on a USB transmission protocol, a micro server or an embedded data board card, and a DDS communication sending end are arranged; a DDS communication receiving end, a local area network switch, and a data display server are arranged at a remote control room; the data acquisition card based on the USB transmission protocol, the micro server or the embedded data board card, and the DDS communication sending end jointly form an integrated data acquisition card, which is arranged at the accelerator site; the integrated data acquisition card is a data acquisition card driven by a small data amount, has relatively high real-time requirements, and has relatively high measurement accuracy; and the data acquisition equipment of the application is located near a radial target of an accelerator, has good signal-to-noise ratio and real-time data processing capability.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cyclotron, and particularly relates to a radial target beam signal monitoring system based on an integrated data acquisition card. BACKGROUND

[0002] The radial target beam signal monitoring system is regarded as the "eyes" of accelerator debugging experiments and plays a crucial role in the experimental process.

[0003] The design difficulty of the radial target beam signal monitoring system lies in the contradiction between the large accelerator site radiation and the relatively weak beam signal. On the one hand, the accelerator site radiation dose is very large, and once the neutron hits the radial target beam signal monitoring system, the device will be damaged. On the other hand, in order to be away from the radiation of the accelerator site, the radial target beam signal monitoring system is usually arranged 100 meters away from the radiation site. Because the farther the distance, the smaller the radiation.

[0004] The radial target beam signal monitoring system arranged at a long distance is divided into two cases, and the second requirement of the second case is the design difficulty of the radial target beam signal monitoring system. It is assumed that the noise of the long-distance signal line in the two cases is 10.

[0005] In the first case, the accelerator current is very strong, and the signal intensity reaches 10,000 after amplification. Therefore, the noise of the long-distance signal line of 10 basically does not cause any influence.

[0006] In the second case, the accelerator current is not so high, and the signal to be measured is in nanoamperes, picoamperes or even smaller. After amplification, the signal can only reach 200. Therefore, the noise of the long-distance signal line of 10 needs to be considered.

[0007] For the second case, further subdivision is needed due to different requirements.

[0008] 1. The first requirement: It is not necessary to see the detailed changes and analysis of the data, but only to know the information of the beam current. The noise caused by the signal line is a random variable. Therefore, we only need to average the signal line noise every second and average the beam current every second to obtain the current size of the second.

[0009] 2. The second requirement: The real beam data of 500k per second without interference need to be seen and further processed, rather than roughly looking at the information. At this time, the noise problem of the beam signal line cannot be ignored.

[0010] In summary, the design challenges of the radial target beam signal monitoring system are: the accelerator main control room is far from the accelerator, the accelerator needs to measure relatively weak beam signals, and the accelerator needs extremely detailed and accurate beam signal data every second.

[0011] Existing radial target beam signal monitoring systems mostly employ a high-speed PCIe card + network cable remote transmission method. Because PCIe data acquisition cards offer high transmission speeds, the preferred method for radial target beam signal monitoring systems in various accelerators is a high-speed PCIe card + network cable remote transmission system. Figure 1 As shown, the system includes a long-distance signal transmission line and a remote control room based on a PCIe data acquisition card, wherein the PCIe data acquisition card is deployed in the remote control room.

[0012] The problem with the above methods is:

[0013] 1) Deploying the PCIe data acquisition card at a remote location is only suitable for the first scenario, not for the second scenario, which is only suitable for situations where the accelerator current is very strong, at the microamp or even milliamp level. After the signal is amplified, its signal strength reaches 10,000. In such cases, the noise of the long-distance signal line is 10, which basically does not cause any impact.

[0014] 2) Self-developed technology is very complex. Because PCIe data acquisition cards have not yet become industrialized, the data acquisition and data transmission functions need to be developed in-house using FPGAs. Each accelerator is developed on FPGAs according to its own needs, which makes FPGA development very complex.

[0015] 3) The method of remote transmission via high-speed PCIe card and network cable usually uses the EPICS or TCP protocol based on gigabit network between the data processing server and the data display server. The EPICS or TCP protocol is not designed for real-time communication and may cause data delay, which does not meet the second requirement of the second case.

[0016] 4) The method of remote transmission using a high-speed PCIe card and network cable is only suitable for placing in a large control room because the PCIe card is relatively large.

[0017] In summary, the existing technologies have the following problems: they are not suitable for long-distance transmission when the beam signal is weak because interference cannot be ignored; using PCIe data acquisition cards requires in-house development, making FPGA development very complex; EPICS or TCP protocols are not suitable for applications with high real-time requirements; and PCIe cards, due to their large footprint, can only be placed in a remote control room. Noise interference refers to the path from the beam signal line to the data acquisition card. When PCIe cards, due to their large footprint, can only be placed in a remote control room, this long path becomes susceptible to interference. Summary of the Invention

[0018] To address the shortcomings of existing technologies, this invention proposes a radial target beam signal monitoring system based on an integrated data acquisition card. The aim is to solve the problems of weak beam signals that are unsuitable for long-distance transmission, the complexity of FPGA development caused by using PCIe data acquisition cards, the insufficient real-time performance of EPICS or TCP protocols, and the large footprint of PCIe cards.

[0019] To solve its technical problems, the present invention proposes the following technical solutions:

[0020] A radial target beam signal monitoring system based on an integrated data acquisition card includes: a short-distance beam signal line deployed at the accelerator site, a data acquisition card based on the USB transmission protocol, a microserver or embedded data board, and a DDS communication transmitter; a DDS communication receiver, a local area network switch, and a data display server deployed in a remote control room; the data acquisition card based on the USB transmission protocol, the microserver or embedded data board, and the DDS communication transmitter together constitute the integrated data acquisition card, which is deployed at the accelerator site;

[0021] Its features are: this integrated data acquisition card is driven by small data volumes, has relatively high real-time requirements, and relatively high measurement accuracy; under small data volume requirements, this data acquisition card based on the USB transmission protocol has a transmission effect comparable to that of the PCIe data acquisition card, and can replace the PCIe card with USB; this DDS communication can achieve the fastest speed.

[0022] Furthermore, the short-distance beam signal line is a beam signal line with a length of 3-5 meters.

[0023] Furthermore, the small data volume refers to 500K*4 channels per second, approximately 2-8Mb of data.

[0024] Furthermore, with a data volume requirement of 500K*4 channels per second and approximately 2-8Mb, the USB data acquisition card performs exactly as well as the PCIe data acquisition card, making it possible to replace the PCIe card with a USB card.

[0025] Furthermore, the USB data acquisition card is a USB 2.0 or USB 3.0 data acquisition card.

[0026] Furthermore, with a requirement of 500K*4 channels per second and approximately 2-8Mb of data per second, DDS communication can achieve the fastest speed.

[0027] Furthermore, the relatively high real-time requirements and relatively high measurement accuracy refer to the high real-time requirements for data display: it is necessary to see 500K*4 uninterrupted real beam data per second and process it further, rather than the average signal line noise level per second or the average beam current intensity measured per second.

[0028] Furthermore, the size of the micro-server or embedded data board is only a fraction of that of a conventional server, making shielding easier and related compatibility protection measures more convenient.

[0029] Furthermore, running a Linux operating system without a character interface on a microserver or embedded data board is more stable and real-time compared to a Windows operating system; and it offers better support for DDS communication development compared to a pure FPGA development system.

[0030] Advantages and effects of the present invention

[0031] 1. The data acquisition device of this invention is located near the radial target of the accelerator, possessing excellent signal-to-noise ratio and real-time data processing capabilities. After oversampling a large amount of data, the data acquisition card transmits it to the data processing server via a high-speed local bus (USB) for real-time data recording and storage. Simultaneously, real-time algorithms are used for data compression, and the processed data is distributed to remote clients via data distribution service technology, with real-time data updates supported by visualization tools.

[0032] 2. Regarding the communication interface, this invention chooses USB as the connection method between the acquisition card and the data server. Compared to UART, USB offers higher transmission efficiency, and at the current data volume level (hundreds of kilobytes), it meets the real-time transmission requirements, just like PCIe. However, USB has greater versatility and scalability; general computers and industrial control computers typically have multiple USB interfaces, while embedded micro-industrial control computers rarely have additional external PCIe interfaces. Furthermore, most commercial and industrial data acquisition cards on the market use USB as the communication interface. Therefore, the beam signal monitoring system developed based on USB is not only compatible with self-developed data acquisition cards, but also allows for monitoring experiments using existing industrial data acquisition cards before the self-developed board is completed.

[0033] 2. For the data processing server, we chose the character-only Linux operating system. Compared to graphical user interface systems like Windows, Linux simplifies operation, improves real-time performance, enhances stability and reliability, and is better suited to the complex environment of the accelerator site. Furthermore, compared to FPGA-only processing methods, it offers advantages such as multi-tasking execution and greater freedom in programming development.

[0034] 3. To achieve efficient communication between the data processing server and the data display server, this invention employs a distributed real-time communication technology—Data Distribution Service (DDS). Compared to traditional TCP and EPICS protocols, DDS is specifically designed for real-time communication, supports a publish-subscribe model, and allows asynchronous data transmission between publishers and subscribers. This reduces latency and optimizes network bandwidth utilization, thereby reducing redundant data transmission and improving real-time performance. Furthermore, DDS uses QoS (Quality of Service) policies to manage the real-time performance of data transmission, adapting to the needs of different application scenarios. This allows this invention to avoid network congestion and data packet loss caused by the TCP protocol under high loads, while EPICS is relatively less flexible in terms of real-time performance and dynamic changes.

[0035] 4. Furthermore, the DDS protocol is compatible with multiple programming languages, and its publish-subscribe model allows for flexible interaction between publishers and subscribers in different programming languages. Data processing servers can choose faster and more stable programming languages ​​according to their needs, while data display servers can utilize programming languages ​​focused on real-time display, fully leveraging the advantages of each programming language to achieve more efficient data processing and presentation. Attached Figure Description

[0036] Figure 1 A schematic diagram of a radial target beam signal monitoring system using existing PCIE+ network transmission technology;

[0037] Figure 2This is a schematic diagram of the radial target beam signal monitoring system based on an integrated data acquisition card according to the present invention. Detailed Implementation

[0038] Design principle of the invention

[0039] 1. Design principle of this invention: The initial design was based on project requirements: ① data with good signal-to-noise ratio and low noise interference; ② high real-time requirements for data display.

[0040] Therefore, given the significant distance between the main control room and the accelerator, and the unacceptable signal-to-noise ratio requirements for long-distance signal lines, embedded technology was employed to process the signals acquired by the accelerator locally. To enable on-site processing, the acquisition and transmission speeds needed to be comparable to PCIe data acquisition cards (data acquisition cards based on the PCIe transmission protocol), while minimizing the size and shielding of the local processing device. Therefore, based on the data volume, a USB data acquisition card was selected. Simultaneously, to achieve ultimate real-time performance, this invention also utilizes DDS communication technology. Considering the technical challenges, the development of a custom FPGA-compatible DDS driver was abandoned, and instead, a micro-server based on a Linux operating system with better DDS support was chosen.

[0041] 2. Extreme conditions led to abandoning conventional methods: First, the main control room was approximately 100 meters from the accelerator site, and the long transmission line posed an extreme condition. Second, the signal strength was in the nanoampere, picoampere, or even lower range, which was also an extreme condition. Third, obtaining extremely detailed, real-time beam signal data per second required exceptionally high data detail, which was another extreme condition. It was precisely under these extreme conditions of long distance, low signal strength, high real-time requirements, and high data detail requirements that some commonly used approaches in this field were abandoned.

[0042] 3. Design principles of this invention

[0043] We don't use EPIC or TCP because real-time requirements are high.

[0044] Long-distance transmission is not used because the signal strength is low and interference cannot be ignored.

[0045] The data acquisition equipment is not placed outside the accelerator because the control room is far from the accelerator, and placing it in the main control room would prevent short-distance transmission.

[0046] We don't use PCIe because it takes up a lot of space, and it's difficult to shield if it's placed near the accelerator.

[0047] FPGA is not used because the extremely high real-time performance of FPGA does not provide as good support for DDS as that of a microserver running a normal Linux operating system.

[0048] 3. Innovation of this invention: The innovation lies in the clever use of two "just right" moments. One "just right" moment is that, with a data volume requirement of 500K*4 channels per second and approximately 2-8Mb of data per second, the transmission performance of the USB data acquisition card is exactly equivalent to that of the PCIe data acquisition card, allowing the USB to replace the PCIe card. The other "just right" moment is that, with a data volume requirement of 500K*4 channels per second and approximately 2-8Mb of data per second, DDS communication achieves its fastest speed. Although the PCIe data acquisition card has a higher transmission rate, because the data volume requirement of this invention is only 500K*4 channels per second and approximately 2-8Mb of data per second, at this level, both the USB data acquisition card and the DDS communication protocol reach their optimal state. Therefore, although the PCIe data acquisition card has a faster transmission rate, it is not used in this embodiment.

[0049] Thanks to the use of USB data acquisition cards and the DDS communication protocol, the integrated data acquisition card (USB data acquisition card + microserver or embedded board) is relatively small, only a fraction of the size of a PCIe data acquisition card + data processing server. This small size allows it to be deployed in shielded cabinets at the accelerator site. This protects the integrated data acquisition card from the strong radiation at the accelerator site and solves the problem of noise interference affecting weak signals during long-distance signal transmission.

[0050] Based on the above-mentioned inventive principles, this invention designs a radial target beam signal monitoring system based on an integrated data acquisition card, comprising: a short-distance beam signal line deployed at the accelerator site, a data acquisition card based on the USB transmission protocol, a microserver or embedded data board, and a DDS communication transmitter; a DDS communication receiver, a local area network switch, and a data display server deployed in a remote control room; the data acquisition card based on the USB transmission protocol, the microserver or embedded data board, and the DDS communication transmitter together constitute the integrated data acquisition card, which is deployed at the accelerator site;

[0051] Its features are: this integrated data acquisition card is driven by small data volumes, has relatively high real-time requirements, and relatively high measurement accuracy; under small data volume requirements, this data acquisition card based on the USB transmission protocol has a transmission effect comparable to that of the PCIe data acquisition card, and can replace the PCIe card with USB; this DDS communication can achieve the fastest speed.

[0052] Additional notes:

[0053] The difference between this invention and existing technologies lies in the placement of the USB data acquisition card and the microserver or embedded board at the accelerator site, moving them from a remote location. The remote location only deploys a display data server and a LAN switch, not a data processing server. Since the microserver or embedded board processes data locally without noise interference, transmitting the processed data to the remote display data server avoids noise interference during the long journey.

[0054] The

[0055] Furthermore, the short-distance beam signal line is a beam signal line with a length of 3-5 meters.

[0056] Furthermore, the small data volume refers to 500K*4 channels per second, approximately 2-8Mb of data.

[0057] Furthermore, with a data volume requirement of 500K*4 channels per second and approximately 2-8Mb, the USB data acquisition card performs exactly as well as the PCIe data acquisition card, making it possible to replace the PCIe card with a USB card.

[0058] Furthermore, the USB data acquisition card is a USB 2.0 or USB 3.0 data acquisition card.

[0059] Furthermore, with a requirement of 500K*4 channels per second and approximately 2-8Mb of data per second, DDS communication can achieve the fastest speed.

[0060] Furthermore, the relatively high real-time requirements and relatively high measurement accuracy refer to the high real-time requirements for data display: it is necessary to see 500K*4 uninterrupted real beam data per second and process it further, rather than the average signal line noise level per second or the average beam current intensity measured per second.

[0061] Furthermore, the size of the micro-server or embedded data board is only a fraction of that of a conventional server, making shielding easier and related compatibility protection measures more convenient.

[0062] Furthermore, running a Linux operating system without a character interface on a microserver or embedded data board is more stable and real-time compared to a Windows operating system; and it offers better support for DDS communication development compared to a pure FPGA development system.

[0063] It should be emphasized that the above specific embodiments are merely explanations of the present invention and are not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to the above embodiments without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A radial target beam signal monitoring system based on an integrated data acquisition card, comprising: Short-distance beam signal lines deployed at the accelerator site, data acquisition cards based on the USB transmission protocol, micro servers or embedded data boards, and data distribution service (DDS) communication transmitters; The data distribution service (DDS) communication receiver, local area network switch, and data display server are deployed in the remote control room; the data acquisition card based on the USB transmission protocol, the micro server or embedded data board, and the data distribution service (DDS) communication transmitter together form an integrated data acquisition card, which is deployed at the accelerator site. Its features include: this integrated data acquisition card is driven by small data volumes, has relatively high real-time requirements, and relatively high measurement accuracy; under small data volume requirements, this USB-based data acquisition card has a transmission effect comparable to that of a PCIe data acquisition card, and can replace the PCIe card with USB; the data distribution service DDS communication can achieve the fastest speed. The short-distance beam signal line is a beam signal line 3-5 meters long; The small data volume refers to 500K*4 channels per second, approximately 2-8Mb of data. The relatively high real-time requirements and relatively high measurement accuracy refer to the high real-time requirements for data display: it is necessary to see 500K*4 uninterrupted real beam data per second and process it further, rather than the average signal line noise level per second or the average beam current intensity measured per second.

2. The radial target beam signal monitoring system based on an integrated data acquisition card according to claim 1, characterized in that: The USB data acquisition card is a USB 2.0 or USB 3.0 data acquisition card.

3. The radial target beam signal monitoring system based on an integrated data acquisition card according to claim 1, characterized in that: The microserver or embedded data board is only a fraction of the size of a conventional server, making shielding easier and related compatibility protection measures more convenient.

4. The radial target beam signal monitoring system based on an integrated data acquisition card according to claim 3, characterized in that: Running a Linux operating system without a character interface on a micro server or embedded data board is more stable and real-time compared to a Windows operating system; and it provides better support for DDS communication development for data distribution services compared to a pure FPGA development system.

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