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

Abstract

The invention discloses a radial target beam signal monitoring system based on an integrated data acquisition card. The radial target beam signal monitoring system is characterized by comprising a short-distance beam signal line arranged on an accelerator site, the data acquisition card based on a USB transmission protocol, a micro server or an embedded data board card and a DDS communication sending end, the DDS communication receiving end, the local area network switch and the data display server are arranged in a far-end 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, and the integrated data acquisition card is arranged on an accelerator site; the integrated data acquisition card is driven by small data magnitude, and is relatively high in real-time requirement and relatively high in measurement precision. The data acquisition equipment is positioned near the radial target of the accelerator, and has good signal-to-noise ratio and real-time data processing capability.

Description

Technical Field

[0001] The invention belongs to the technical field of cyclotron accelerators, and in particular relates to a radial target beam signal monitoring system based on an integrated data acquisition card. Background Art

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

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

[0004] There are two cases for the remote deployment of radial target beam signal monitoring system. The second requirement of the second case is the design difficulty of the radial target beam signal monitoring system. Assume that the noise of the long-distance signal line in both cases is 10.

[0005] In the first case, the accelerator current is very strong, in the microampere or even milliampere range. After the signal is amplified, its own signal strength reaches 10,000. Then the long-distance signal line noise of 10 basically does not cause this impact.

[0006] In the second case, the accelerator current intensity is not that high, and the signal to be measured is in nanoamperes, picoamperes or even smaller. This signal can only reach 200 after amplification, so the noise of the long-distance signal line is 10, which needs to be taken into consideration.

[0007] For the second situation, it is further subdivided due to different needs.

[0008] 1. The first requirement: You don’t need to see the detailed changes in the data and analyze them, you only need to know the information about the beam current intensity. It is known that the noise caused by the signal line is a random variable, so we only need to average the signal line noise every second and average the beam current intensity measurement every second, and then subtract them to get the current intensity of that second.

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

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

[0011] The radial target beam signal monitoring system of the prior art mostly adopts the method of high-speed PCIE card + network cable remote transmission. Because the PCIE data acquisition card has a fast transmission speed, the first choice for the radial target beam signal monitoring system of each accelerator is: high-speed PCIE card + network cable remote transmission system, such as Figure 1 As shown, the system includes a long-distance signal transmission line + a remote control room based on a PCIE data acquisition card, wherein the PCIE data acquisition card is arranged in the remote control room.

[0012] The problems with the above methods are:

[0013] 1) Placing the PCIE data acquisition card at the remote end is only applicable to the first case, but not to the second requirement of the second case. That is, it is only applicable when the accelerator current is very strong, in the microampere or even milliampere level. After the signal is amplified, its own signal strength reaches 10,000. Then the long-distance signal line noise is 10, which basically does not cause this impact.

[0014] 2) Self-development is very complicated. Since PCIE data acquisition cards have not yet become industrialized data acquisition cards, they need to be self-developed using FPGA for data acquisition and data transmission functions. Each accelerator is developed on FPGA according to its own needs, which makes FPGA development very complicated.

[0015] 3) The high-speed PCIE card + network cable remote transmission method usually uses 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 delays, which does not meet the second requirement of the second situation.

[0016] 4) High-speed PCIE card + network cable remote transmission method. Since the PCIE board is relatively large in size, it is only suitable for placement in a main control room with a relatively large space.

[0017] In summary, the existing technology has the following problems: when the beam signal is relatively weak, it is not suitable for long-distance transmission because the interference cannot be ignored; the use of PCIE data acquisition cards requires self-development, which makes FPGA development very complicated; epics or tcp protocols are not suitable for occasions with high real-time requirements; PCIE cards can only be placed in a remote control room because of their large footprint. Noise interference refers to the distance from the beam signal line to the data acquisition card. When the PCIE card can only be placed in a remote control room because of its large footprint, the distance from the beam signal line to the PCIE card is too long and is interfered. Summary of the invention

[0018] In view of the shortcomings of the prior art, the present invention proposes a radial target beam signal monitoring system based on an integrated data acquisition card, aiming to solve the problem that the beam signal is relatively weak and not suitable for long-distance transmission, the problem that the use of PCIE data acquisition card leads to very complicated FPGA development, the problem that the real-time performance of epics or tcp protocols is not good enough, and the problem that the PCIE card occupies a large area.

[0019] The present invention proposes the following technical solutions to solve the technical problems:

[0020] A radial target beam signal monitoring system based on an integrated data acquisition card comprises: a short-distance beam signal line 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; a DDS communication receiving end arranged in a remote control room, a local area network switch, and a data display server; 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 together constitute an integrated data acquisition card, and the integrated data acquisition card is arranged at the accelerator site;

[0021] Its characteristics are: the integrated data acquisition card is driven by small data volume, has relatively high real-time requirements and relatively high measurement accuracy; under the demand for small data volume, the data acquisition card based on the USB transmission protocol has the same transmission effect as the PCIE data acquisition card, and the PCIE card can be replaced by USB; the 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 is 500K*4 channels per second, about 2-8Mb data volume.

[0024] Furthermore, under the requirement of 500K*4 channels per second and about 2-8Mb data level, the transmission effect of USB data acquisition card is just equivalent to that of PCIE data acquisition card, and USB can replace PCIE card.

[0025] Furthermore, the USB data acquisition card is a USB2.0 or USB3.0 data acquisition card.

[0026] Furthermore, with a data rate of 500K*4 channels per second and about 2-8Mb, DDS communication can just reach 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 undisturbed real beam data per second and further process it, rather than the average signal line noise size per second and the average beam current intensity measurement size per second.

[0028] Furthermore, the volume of the micro server or embedded data board is only a fraction of that of a conventional server, so shielding is easier to do and related compatibility protection measures are more convenient.

[0029] Furthermore, the Linux operating system without a character interface running on the micro server or embedded data board is more stable and real-time than the Windows operating system; and has better support for DDS communication development than the pure FPGA development system.

[0030] Advantages and effects of the present invention

[0031] 1. The data acquisition device of the present invention is located near the radial target of the accelerator and has a good signal-to-noise ratio and real-time data processing capability. After the data acquisition card performs oversampling of a large amount of data, it is transmitted to the data processing server through a high-speed local bus (USB) to record and store the data in real time. At the same time, a real-time algorithm is used to compress the data, and the processed data is distributed and delivered to the remote client through the data distribution service technology. With the support of visualization tools, the data is updated in real time.

[0032] 2. In terms of communication interface, the present invention selects USB as the connection method between the acquisition card and the data server. Compared with UART, USB provides higher transmission efficiency, and at the current data level (hundreds of kb), it meets the needs of real-time transmission like PCIE. However, USB has higher versatility and scalability. General computers and industrial computers usually have multiple USB interfaces, while embedded micro industrial computers rarely have additional external PCIE interfaces. In addition, 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 can use existing industrial data acquisition cards for monitoring experiments before the self-developed boards are completed.

[0033] 2. On the data processing server, we chose the Linux operating system with only a character interface. Compared with graphical interface systems such as Windows, the Linux system simplifies operation, improves real-time performance, enhances stability and reliability, and is more adaptable to the complex environment of the accelerator site. Compared with the FPGA-only processing method, it has the advantages of multi-tasking execution and higher programming freedom.

[0034] 3. In order to achieve efficient communication between the data processing server and the data display server, the present invention adopts a distributed real-time communication technology - Data Distribution Service (DDS). Compared with the traditional TCP and EPICS protocols, DDS is designed for real-time communication and supports the publish-subscribe model, allowing data to be transmitted asynchronously between publishers and subscribers, reducing latency and optimizing network bandwidth utilization, thereby reducing redundant data transmission and improving real-time performance. In addition, DDS uses QoS (Quality of Service) strategies to manage the real-time nature of data transmission to meet the needs of different application scenarios. This enables the present invention to avoid network congestion and data packet loss caused by the TCP protocol when facing high loads, while EPICS is relatively inflexible in terms of real-time performance and dynamic changes.

[0035] 4. In addition, the DDS protocol is compatible with a variety of development programming languages, and its publish-subscribe model allows flexible interaction between publishers and subscribers of different programming languages. The data processing server can choose a faster and more stable development language according to demand, while the data display server can use a development language that focuses on real-time display, giving full play to the advantages of each programming language, thereby achieving more efficient data processing and display. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of a radial target beam signal monitoring system for PCIE+ network transmission in the prior art;

[0037] Figure 2It is a schematic diagram of the radial target beam signal monitoring system based on the integrated data acquisition card of the present invention. DETAILED DESCRIPTION

[0038] Design principle of the present invention

[0039] 1. Design principle of the present invention: The original intention of the design is the project requirements: ① requiring data with good signal-to-noise ratio and good noise interference; ② requiring high real-time performance of data display.

[0040] Therefore, when the main control room is far from the accelerator itself and the signal-to-noise ratio requirement does not allow the use of long-distance signal lines, embedded technology is used to process the signals collected by the accelerator in situ near the accelerator. In order to process the accelerator in situ, it is necessary to make the equipment processed in situ as small as possible, and easy to shield and protect, under the condition that the acquisition speed and transmission speed are no less than those of the PCIE data acquisition card (data acquisition card based on the PCIE transmission protocol), so as to pursue the ultimate real-time performance, the present invention adopts DDS communication technology, comprehensively considers the technical difficulty, abandons the self-developed FPGA compatible with DDS driver, and selects the micro server of Linux operating system with better support for DDS.

[0041] 2. Extreme conditions led to the abandonment of conventional methods: First, the main control room is about 100 meters away from the accelerator site, and the transmission line is very long, which is an extreme condition. Second, the signal strength is nanoamperes, picoamperes or even smaller, and the signal strength is low, which is an extreme condition; third, to see extremely detailed real beam signal data every second, the requirement for data details is an extreme condition. It is precisely because of these extreme conditions of long distance, low signal strength, high real-time requirements, and high data detail requirements that some common routes in this field have been abandoned.

[0042] 3. Design principles of the present invention

[0043] Do not use epics or tcp because of the high real-time requirements.

[0044] There is no need for long-distance transmission because the signal strength is low and interference cannot be ignored.

[0045] The acquisition equipment is not placed outside the accelerator because the control room is far away from the accelerator, and short-distance transmission is not possible if it is placed in the main control room.

[0046] PCIE is not used because it takes up a lot of space and is placed near the accelerator, making shielding difficult.

[0047] FPGA is not used because the extremely real-time FPGA does not support DDS as well as the microserver running the Linux operating system.

[0048] 3. Innovation of the present invention: The innovation lies in the clever use of two "just right". One "just right" is: under the requirements of 500K*4 channels per second and about 2-8Mb data level, the transmission effect of the USB data acquisition card is just equivalent to that of the PCIE data acquisition card, and the PCIE card can be replaced by USB; the other "just right" is: under the requirements of 500K*4 channels per second and about 2-8Mb data level, DDS communication can just reach the fastest speed. Although the transmission rate of the PCIE data acquisition card is higher, because the data volume requirement of the present invention is only 500K*4 channels per second and about 2-8Mb data level, at this level, both the USB data acquisition card and the DDS communication protocol reach the best state, so, although the PCIE data acquisition card has a faster transmission rate, it is not used in this embodiment.

[0049] Due to the use of USB data acquisition card and DDS communication protocol, the volume of the integrated data acquisition card (USB data acquisition card + micro server or embedded board) is relatively small, only a fraction of the PCIE data acquisition card + data processing server. Since the integrated data acquisition card is very small, it can be deployed in the shielded cabinet at the accelerator site. In this way, it is ensured that the integrated data acquisition card is not damaged by the strong radiation at the accelerator site, and the problem of weak signals being interfered by noise during long-distance signal transmission is solved.

[0050] Based on the above invention principle, the present invention designs a radial target beam signal monitoring system based on an integrated data acquisition card, comprising: a short-distance beam signal line arranged at the 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; a DDS communication receiving end arranged in a remote control room, a local area network switch, and a data display server; the data acquisition card based on a USB transmission protocol, the micro server or the embedded data board card, and the DDS communication sending end together constitute an integrated data acquisition card, and the integrated data acquisition card is arranged at the accelerator site;

[0051] Its characteristics are: the integrated data acquisition card is driven by small data volume, has relatively high real-time requirements and relatively high measurement accuracy; under the demand for small data volume, the data acquisition card based on the USB transmission protocol has the same transmission effect as the PCIE data acquisition card, and the PCIE card can be replaced by USB; the DDS communication can achieve the fastest speed.

[0052] Additional notes:

[0053] The difference between the present invention and the prior art is that the USB data acquisition card and the micro server or embedded board are placed from the remote end to the accelerator site, and only the display data server and the LAN switch are arranged at the remote end, but not the data processing server. Since the micro server or embedded board processes the data without being disturbed by noise at the near end, the processed data is transmitted to the display data server at the remote end, and will not be disturbed by noise due to the "long journey".

[0054] Said

[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 is 500K*4 channels per second, about 2-8Mb data volume.

[0057] Furthermore, under the requirement of 500K*4 channels per second and about 2-8Mb data level, the transmission effect of USB data acquisition card is just equivalent to that of PCIE data acquisition card, and USB can replace PCIE card.

[0058] Furthermore, the USB data acquisition card is a USB2.0 or USB3.0 data acquisition card.

[0059] Furthermore, with a data rate of 500K*4 channels per second and about 2-8Mb, DDS communication can just reach 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 undisturbed real beam data per second and further process it, rather than the average signal line noise size per second and the average beam current intensity measurement size per second.

[0061] Furthermore, the volume of the micro server or embedded data board is only a fraction of that of a conventional server, so shielding is easier to do and related compatibility protection measures are more convenient.

[0062] Furthermore, the Linux operating system without a character interface running on the micro server or embedded data board is more stable and real-time than the Windows operating system; and has better support for DDS communication development than the pure FPGA development system.

[0063] It should be emphasized that the above specific embodiments are merely explanations of the present invention, and they are not limitations of the present invention. After reading this specification, those skilled in the art can make modifications to the above embodiments without any creative contribution as needed, 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, USB-based data acquisition cards, micro servers or embedded data boards, and DDS communication transmitters are deployed at the accelerator site. The DDS communication receiving end, the LAN switch, and the data display server are arranged in the 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 together constitute an integrated data acquisition card, which is arranged at the accelerator site; The characteristics are as follows: the integrated data acquisition card is driven by small data volume, has relatively high real-time requirements and relatively high measurement accuracy; under the requirement of small data volume, the data acquisition card based on USB transmission protocol has the same transmission effect as PCIE data acquisition card, and USB can replace PCIE card; the DDS communication can achieve the fastest speed.

2. The radial target beam signal monitoring system based on an integrated data acquisition card according to claim 1, characterized in that: The short-distance beam signal line is a beam signal line with a length of 3-5 meters.

3. The radial target beam signal monitoring system based on an integrated data acquisition card according to claim 1, characterized in that: The small data volume is 500K*4 channels per second, about 2-8Mb data volume.

4. The radial target beam signal monitoring system based on an integrated data acquisition card according to claim 3, characterized in that: With the requirement of 500K*4 channels per second and about 2-8Mb data volume, the transmission effect of USB data acquisition card is just equivalent to that of PCIE data acquisition card, and PCIE card can be replaced by USB.

5. The radial target beam signal monitoring system based on an integrated data acquisition card according to claim 4, characterized in that: The USB data acquisition card is a USB2.0 or USB3.0 data acquisition card.

6. The radial target beam signal monitoring system based on an integrated data acquisition card according to claim 3, characterized in that: With the demand of 500K*4 channels per second and about 2-8Mb data volume, DDS communication can just reach the fastest speed.

7. The radial target beam signal monitoring system based on an integrated data acquisition card according to claim 1, characterized in that: 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 undisturbed real beam data per second and further process it, rather than the average signal line noise size per second and the average beam current intensity measurement size per second.

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

9. The radial target beam signal monitoring system based on an integrated data acquisition card according to claim 8, characterized in that: The Linux operating system without a character interface running on the micro server or embedded data board is more stable and real-time than the Windows operating system; it has better support for DDS communication development than the pure FPGA development system.

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