Level adjustable threshold input system for RS232 serial communication card

Abstract

The invention provides a level adjustable threshold input system for an RS232 serial communication card, which belongs to the technical field of serial communication cards and comprises an upper computer communication interface, a master controller, a data buffer, a high DAC, a low DAC, a filtering module, a level shifter, a buffer amplifier, a high comparator, a low comparator, a TVS input protection circuit, a power conversion module and a power interface. The level can be adjusted, different requirements are met, and noise interference is filtered and removed. TVS protection prevents transient high voltage, and stable power supply is ensured through power supply conversion. The comparator accurately judges the level, and the buffer amplifier enhances and isolates the signal. Data caching avoids data loss, and a master control coordinates system operation.

Description

Technical Field

[0001] The invention relates to the field of serial port communication cards, in particular to a level-adjustable input system for RS232 serial port communication cards. Background Art

[0002] In the existing RS232 serial communication, the level-adjustable threshold input structure has the following problems:

[0003] Incompatible levels: The RS232 standard defines specific voltage ranges (usually +3V to +15V for logic "0" and -3V to -15V for logic "1"). If the adjustable output structure is not accurately adjusted to these voltage ranges, it may cause unstable or failed communications with other devices.

[0004] Input stability: Level-adjustable inputs may introduce noise or instability when adjusting the voltage, especially when the load changes. If the output level is unstable, it may cause bit errors during data transmission.

[0005] Response time: The level-adjustable input structure may have a delay when adjusting the level, which is a problem for serial communication that requires a fast response. Especially in the case of high-frequency data transmission, the delay in response time may affect the overall communication efficiency.

[0006] Current input capability: RS232 communication usually requires a certain current output capability. If the current output capability of the level-adjustable input structure is insufficient, it may cause signal attenuation and affect the reliability of long-distance transmission.

[0007] Overheating: When working under high load for a long time, the level-adjustable input structure may overheat, resulting in performance degradation or failure. A reasonable heat dissipation solution needs to be designed.

[0008] Electrical isolation: Lack of proper electrical isolation may result in ground loop problems between different devices, causing signal interference or damaging the equipment.

[0009] Therefore, there is an urgent need in the art for a level-adjustable threshold input system for an RS232 serial port communication card that can solve one or more of the above problems.

[0010] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0011] The purpose of the present invention is to provide a technical solution with level compatibility, stable output, low response delay, strong current output capability, good heat dissipation and electrical isolation.

[0012] To achieve the above object, the present invention provides the following solutions:

[0013] A level-adjustable input system for an RS232 serial port communication card, comprising:

[0014] Host computer communication interface, main control, data buffer, high DAC, low DAC, filter module, level converter, buffer amplifier, high comparator, low comparator, TVS input protection circuit, power conversion module and power interface;

[0015] The host computer communication interface is connected to the main control, the main control is connected to the data buffer, the level converter, the high DAC and the low DAC, the high DAC and the low DAC are respectively connected to the filter module, the filter module is connected to the buffer amplifier, the level converter is respectively connected to the high comparator and the low comparator, and the high comparator and the low comparator are connected to the TVS input protection circuit.

[0016] Optionally, the host computer communication interface is used for communication between the board and the host computer, using PCI, PCIe, CPCI, PXIe, USB and Ethernet interface methods.

[0017] Optionally, the main control is an FPGA or a high-speed single-chip microcomputer, which is used to parse host computer instructions and return received data to the host computer. The main control is also used to control DAC to adjust the input high level threshold and low level threshold.

[0018] Optionally, the data buffer is used to cache received input data in a first-in-first-out mode, and when the host computer interface is not busy, the received data is uploaded to the host computer in a timely manner.

[0019] Optionally, the high DAC and the low DAC are used to generate high and low level thresholds of the serial port input respectively, the high DAC and the low DAC are controlled by a main control chip, and the specific set voltage value is issued by a host computer.

[0020] Optionally, the buffer amplifier is used to amplify the high DAC and low DAC voltages and provide greater driving current capability.

[0021] Optionally, the input signal is connected to the input terminals of the high comparator and the low comparator at the same time, and the comparator selects a comparator with an operating voltage range of 0-40V, which can adapt to the high level voltage and low level voltage range of the serial port;

[0022] The TVS protector is used to protect the buffer amplifier from being affected by the external surge signal.

[0023] Optionally, the input signal is compared with the high level threshold and the low level threshold respectively through the high comparator and the low comparator, and there are three comparison results: higher than the high limit, lower than the high limit but higher than the low limit, and lower than the low limit; the output voltage of the comparator is relatively high and is not suitable for the master control to receive, and a level converter is used to convert the comparator output into a level standard acceptable to the master control;

[0024] The master controller determines whether the input signal is high level, low level or uncertain state by obtaining the output of two level converters;

[0025] One master control can configure multiple input channels with adjustable thresholds;

[0026] By adjusting the high and low thresholds of the adjustable threshold input channel, it is possible to test whether the level voltage of the input signal meets expectations.

[0027] Optionally, the main control internal program logic is used to determine whether the receiving end has compliant data. If the signal conforms to the UART protocol, the main control can obtain the digital sequence of the input signal, store the sequence data in the buffer area, set the flag bit to indicate that there is new data, and the host computer can obtain the new data.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention provides a level-adjustable threshold input system for an RS232 serial communication card, comprising: a host computer communication interface, a main control, a data buffer, a high DAC, a low DAC, a filter module, a level converter, a buffer amplifier, a high comparator, a low comparator, a TVS input protection circuit, a power conversion module and a power interface;

[0030] 1. Communication and data processing

[0031] Stable data transmission:

[0032] The host computer communication interface ensures the connection with external devices (such as computers and other host computer devices) and provides a channel for data input and output. The transceiver chip is responsible for converting between different level standards to ensure the normal RS232 serial communication.

[0033] The master controller controls the entire system and coordinates the work of each component. The data buffer can temporarily store data to avoid loss or congestion during data transmission, thereby improving the stability and reliability of data transmission.

[0034] Flexible level control:

[0035] The existence of high-level DAC and low-level DAC enables the system to adjust the input level. This is very useful in different application scenarios. For example, when communicating with external devices with different level requirements, the DAC output level can be adjusted to match the input level requirements of the external device.

[0036] 2. Signal quality

[0037] Signal filtering and amplification:

[0038] The filter can filter the output signal, remove the noise and interference components in the signal, and improve the purity of the signal. The buffer amplifier can amplify the filtered signal and enhance the signal strength so that it can better drive external devices.

[0039] Protection function:

[0040] TVS protectors can protect the system from instantaneous high voltage pulses (such as those caused by electrostatic discharge, electromagnetic interference, etc.) causing damage to the system, thereby improving the stability and reliability of the system and extending the service life of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0042] Figure 1 A schematic diagram of the system structure provided by an embodiment of the present invention.

[0043] Figure 2 A schematic diagram of the structure of a TVS input protection circuit provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] The purpose of the present invention is to provide a technical solution with level compatibility, stable output, low response delay, strong current output capability, good heat dissipation and electrical isolation.

[0046] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] Embodiment 1:

[0048] This embodiment provides a level-adjustable threshold input system for an RS232 serial communication card, such as Figure 1 As shown, including:

[0049] Host computer communication interface, main control, data buffer, high DAC, low DAC, filter module, level converter, buffer amplifier, high comparator, low comparator, TVS input protection circuit, power conversion module and power interface;

[0050] The host computer communication interface is connected to the main control, the main control is connected to the data buffer, the level converter, the high DAC and the low DAC, the high DAC and the low DAC are respectively connected to the filter module, the filter module is connected to the buffer amplifier, the level converter is respectively connected to the high comparator and the low comparator, and the high comparator and the low comparator are connected to the TVS input protection circuit.

[0051] Furthermore, the host computer communication interface is used for communication between the board and the host computer, and adopts PCI, PCIe, CPCI, PXIe, USB and Ethernet interface methods.

[0052] Furthermore, the main control is an FPGA or a high-speed single-chip microcomputer, which is used to parse the host computer instructions and return the received data to the host computer. The main control is also used to control the DAC to adjust the input high level threshold and low level threshold.

[0053] Furthermore, the data buffer is used to buffer received input data in a first-in-first-out mode, and when the host computer interface is not busy, the received data is uploaded to the host computer in a timely manner.

[0054] Furthermore, the high DAC and the low DAC are used to generate high and low level thresholds of the serial port input respectively. The high DAC and the low DAC are controlled by the main control chip, and the specific set voltage value is issued by the host computer.

[0055] Furthermore, the buffer amplifier is used to amplify the high DAC and low DAC voltages and provide a greater driving current capability.

[0056] Further, the input signal is connected to the input terminals of the high comparator and the low comparator at the same time, and the comparator selects a comparator with an operating voltage range of 0-40V, which can adapt to the high level voltage and low level voltage range of the serial port;

[0057] The TVS protector is used to protect the buffer amplifier from being affected by the external surge signal.

[0058] Furthermore, the input signal is compared with the high level threshold and the low level threshold respectively through the high comparator and the low comparator. There are three comparison results: higher than the high limit, lower than the high limit but higher than the low limit, and lower than the low limit. The output voltage of the comparator is relatively high and is not suitable for the master control to receive. A level converter is used to convert the comparator output into a level standard acceptable to the master control.

[0059]

[0060] The master controller determines whether the input signal is high level, low level or uncertain state by obtaining the output of two level converters;

[0061] One master control can configure multiple input channels with adjustable thresholds;

[0062] By adjusting the high and low thresholds of the adjustable threshold input channel, it is possible to test whether the level voltage of the input signal meets expectations.

[0063] Furthermore, the main control internal program logic is used to determine whether there is compliant data at the receiving end. If the signal conforms to the UART protocol, the main control can obtain the digital sequence of the input signal, store the sequence data in the buffer area, set the flag bit to indicate that there is new data, and the host computer can obtain the new data.

[0064] 1. Signal processing

[0065] Level Adjustability:

[0066] The presence of high DAC and low DAC enables the input threshold level to be adjusted. This means that the system can adapt to different signal level standards or different device connection requirements. For example, in different industrial environments, the RS232 serial port levels of various devices may have certain deviations. By adjusting the threshold level, it can ensure accurate reception and recognition of signals, thereby improving the compatibility of the system.

[0067] Filtering function:

[0068] The filter module helps to remove noise and interference from the signal. In the actual serial communication environment, there may be various electromagnetic interferences, such as radio frequency interference from other devices or noise on the power line. The filter module can filter out these unnecessary signal components, making the transmitted signal purer, thereby improving the accuracy and reliability of data transmission.

[0069] 2. Circuit protection

[0070] TVS input protection circuit:

[0071] The TVS (Transient Voltage Suppressor) input protection circuit can prevent excessive transient voltage from damaging the system. For example, when the system is struck by lightning or spikes from other electrical equipment, the TVS circuit can clamp the excessive voltage within a safe range and protect other sensitive components in the system, such as the main control chip, comparator, etc., thereby improving the stability and durability of the entire system.

[0072] Power conversion module:

[0073] The power conversion module helps ensure that each part of the system receives the appropriate power supply. It can convert the external input power into the voltage level required by different components within the system, such as providing a stable operating voltage for high DAC, low DAC, comparator, etc. A stable power supply is essential for the normal operation of the system and can reduce signal processing errors caused by power fluctuations.

[0074] 3. Signal comparison and amplification

[0075] High Comparator and Low Comparator:

[0076] The high comparator and the low comparator can accurately compare and judge the input signal. By setting the appropriate comparison threshold (adjusted by the high DAC and the low DAC), the logic level of the signal can be accurately determined, such as distinguishing between high and low level signals, which is very critical for correctly decoding the data bits in the serial communication.

[0077] Buffer Amplifier:

[0078] Buffer amplifiers can amplify and buffer signals. During signal transmission, the signal amplitude may decrease due to line loss and other reasons. Buffer amplifiers can enhance the strength of the signal and isolate the front and rear circuits to prevent mutual influence between the front and rear circuits and improve the quality of signal transmission.

[0079] 4. Data Processing

[0080] Data Buffer:

[0081] The data buffer can temporarily store data. In serial communication, the data transmission speed may not completely match the speed at which the system processes data. The data buffer can temporarily store data in the gap between data transmissions, waiting for the main control chip to process, avoiding data loss and improving the system's data processing capabilities and data transmission integrity.

[0082] Main control function:

[0083] The main control chip plays a role in coordination and control in the whole system. It can process the data received from the serial port, such as decoding and verification according to the communication protocol, and control the work of other components, such as controlling the output of high DAC and low DAC to adjust the threshold level to ensure the orderly operation of the whole system.

[0084] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0085] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A level-adjustable threshold input system for RS232 serial communication card, characterized in that: include: Host computer communication interface, main control, data buffer, high DAC, low DAC, filter module, level converter, buffer amplifier, high comparator, low comparator, TVS input protection circuit, power conversion module and power interface; The host computer communication interface is connected to the main control, the main control is connected to the data buffer, the level converter, the high DAC and the low DAC, the high DAC and the low DAC are respectively connected to the filter module, the filter module is connected to the buffer amplifier, the level converter is respectively connected to the high comparator and the low comparator, and the high comparator and the low comparator are connected to the TVS input protection circuit.

2. The level-adjustable threshold input system for RS232 serial communication card according to claim 1, characterized in that: The host computer communication interface is used for communication between the board and the host computer, and adopts PCI, PCIe, CPCI, PXIe, USB and Ethernet interface methods.

3. The level-adjustable threshold input system for RS232 serial communication card according to claim 1, characterized in that: The main control is an FPGA or a high-speed single-chip microcomputer, which is used to parse the host computer instructions and return the received data to the host computer. The main control is also used to control the DAC to adjust the input high level threshold and low level threshold.

4. The level-adjustable threshold input system for RS232 serial communication card according to claim 1, characterized in that: The data buffer is used to buffer received input data in a first-in-first-out mode, and when the host computer interface is not busy, the received data is uploaded to the host computer in a timely manner.

5. The level-adjustable threshold input system for RS232 serial communication card according to claim 1, characterized in that: The high DAC and the low DAC are used to generate high and low level thresholds of the serial port input respectively. The high DAC and the low DAC are controlled by the main control chip, and the specific set voltage value is issued by the host computer.

6. The level-adjustable threshold input system for RS232 serial communication card according to claim 1, characterized in that: The buffer amplifier is used to amplify the high DAC and low DAC voltages and provide a greater driving current capability.

7. The level-adjustable threshold input system for RS232 serial communication card according to claim 1, characterized in that: The input signal is connected to the input terminals of the high comparator and the low comparator at the same time. The comparator selects a comparator with an operating voltage range of 0-40V, which can adapt to the high level voltage and low level voltage range of the serial port; The TVS protector is used to protect the buffer amplifier from being affected by the external surge signal.

8. The level-adjustable threshold input system for RS232 serial communication card according to claim 1, characterized in that: The input signal is compared with the high level threshold and the low level threshold respectively through the high comparator and the low comparator. There are three comparison results: higher than the high limit, lower than the high limit but higher than the low limit, and lower than the low limit. The output voltage of the comparator is too high to be received by the master control. A level converter is used to convert the comparator output to a level standard acceptable to the master control. The master controller determines whether the input signal is high level, low level or uncertain state by obtaining the output of two level converters; One master control can configure multiple input channels with adjustable thresholds; By adjusting the high and low thresholds of the adjustable threshold input channel, it is possible to test whether the level voltage of the input signal meets expectations.

9. The level-adjustable threshold input system for RS232 serial communication card according to claim 1, characterized in that: Through the internal program logic of the main control, it is determined whether there is compliant data at the receiving end. If the signal conforms to the UART protocol, the main control can obtain the digital sequence of the input signal, store the sequence data in the buffer area, set the flag bit to indicate that there is new data, and the host computer can obtain the new data.

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