A multi-channel analog input / output board card

Abstract

This utility model relates to the field of data transmission technology, and in particular to a multi-channel analog input / output board, including an FPGA core board, and an analog input module, an analog output module, a power supply module, and a bus interface module connected to the FPGA core board. Both the analog input module and the analog output module are connected to a signal interface module. The signal interface module includes multiple single-ended and multiple differential analog input channels, and multiple single-ended and multiple differential analog output channels. The analog input module includes, in sequence, an analog input protection circuit, a resistor divider circuit, an analog switch circuit, a gain-controlled operational amplifier circuit, and an AD converter. The analog output module is a conditioning circuit composed of a DAC digital-to-analog converter and a voltage follower. This utility model provides a new generation of boards with higher density, wider signal range, stronger synchronization capability, and a standard flexible interface.

Description

Technical Field

[0001] This utility model relates to the field of data transmission technology, and in particular to a multi-channel analog input / output board. Background Technology

[0002] Analog input / output (I / O) boards, as key interface components in industrial automation systems, undertake the core task of bidirectional conversion between continuous analog signals in the physical world and digital control systems. They are widely used in industrial scenarios requiring high precision and real-time performance, such as intelligent manufacturing, process control, and testing and measurement. However, despite continuous technological advancements, many existing analog I / O boards on the market still exhibit significant limitations in several key dimensions when dealing with complex and ever-changing application requirements, hindering the improvement of overall system performance and application flexibility. Their shortcomings are mainly reflected in the following aspects: First, there is a significant bottleneck in terms of channel capacity. Many boards have a limited number of analog input (AI) and output (AO) channels. When industrial sites require the simultaneous monitoring of a large number of sensors (such as temperature, pressure, and displacement sensors) or the control of multiple actuators (such as frequency converters, servo drives, and proportional valves), the limited number of channels means that users must install multiple boards. This not only significantly increases hardware costs and occupies more control system slot space, but also complicates wiring, reduces system integration and reliability, and makes it difficult to meet the demands of modern industry for centralized, high-density signal processing.

[0003] Secondly, the adaptability of the signal voltage range is insufficient. Existing boards typically have narrow preset input and output signal voltage ranges, such as supporting only 0-5V or 0-10V standard signals. However, signal sources and load devices in industrial environments vary widely, potentially involving small signals at the millivolt level (such as thermocouples), higher-level signals (such as ±15V), or current signals (such as 4-20mA). This narrow voltage range prevents the boards from directly adapting to these different amplitude signals, forcing users to configure additional signal conditioners or conversion modules. This not only introduces additional error points and costs but also increases the complexity of system configuration.

[0004] Finally, the compatibility and scalability of external interfaces are poor. The interface standards for connecting the board to external devices vary; some use traditional terminal blocks, while others may use specific types of connectors. This inconsistency makes it difficult to easily connect to sensors, actuators, or third-party devices that adhere to different industry standards, reducing system interoperability. Furthermore, the lack of modular or scalable interface design also poses difficulties for users when facing future system upgrades or functional expansions.

[0005] In summary, the shortcomings of existing analog input / output boards in terms of channel density, signal adaptability, and interface compatibility have become key factors restricting the full realization of the effectiveness of advanced industrial control systems. Utility Model Content

[0006] The purpose of this invention is to provide a multi-channel analog input / output board. This analog board adopts a multi-channel design, providing multiple single-ended and multiple differential analog input channels as well as multiple single-ended and multiple differential analog output channels. The input channels use voltage divider circuits and programmable gain amplifiers to achieve analog signal input with a wide voltage range. The output channels use high-precision digital-to-analog converters and voltage followers to achieve analog signal output with a wide voltage range, thereby overcoming the aforementioned problems.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A multi-channel analog input / output board is characterized in that it includes an FPGA core board, an analog input module, an analog output module, a power supply module, a signal interface module, and a bus interface module. The FPGA core board is connected to the analog input module, the analog output module, the power supply module, and the bus interface module, respectively. The analog input module and the analog output module are both connected to the signal interface module. The signal interface module adopts a SCSI signal interface, which includes multiple single-ended and multiple differential analog input channels, and multiple single-ended and multiple differential analog output channels; The analog input module includes an analog input protection circuit, a resistor voltage divider circuit, an analog switch circuit, a gain-controllable operational amplifier circuit, and an AD converter connected in sequence. The analog output module is a conditioning circuit consisting of a DAC digital-to-analog converter and a voltage follower.

[0008] Furthermore, the FPGA core board is an FPGA core board built with XC7A100TXC7A100T chips. The FPGA core board is connected to the analog input module, analog output module and power module through high-speed inter-board connectors, and is modularly connected to the bus interface through a PCI-to-PCIe bridge.

[0009] Furthermore, a resettable fuse is connected after the voltage follower.

[0010] Furthermore, the bus interface module is implemented using a CPCI interface, and the PCI bus is connected to the FPGA core board using a PCI-to-PCIe bridge; the CPCI interface provides the operating power required by the board.

[0011] Furthermore, the power module includes a power switch circuit, a fuse, a reverse connection protection circuit, and a filter in sequence, and multiple DC / DC converters are connected after the filter; One DC / DC converter is connected to the power supply circuit of the FPGA core board; Two DC / DC converters convert 5V to 3.3V and 1V respectively to provide input voltage for other circuits; The two-channel DC / DC converter transforms 5V into +15V and -15V respectively to provide power to the gain-controlled operational amplifier circuit, AD converter and DAC digital-to-analog converter; One DC / DC converter converts 5V to 2.5V to provide a reference voltage.

[0012] Compared with the prior art, the present invention has the following beneficial effects: (1) Multi-channel analog input; external analog signals enter through the SCSI interface, and the signal is reduced to the acceptable range of the ADC through the voltage divider circuit; then different channels are selected through analog switches, and the signal amplitude is adjusted by the programmable gain amplifier and then converted into digital signals by the high-precision ADC; the FPGA receives the digital signals and processes them, and finally transmits them to the host computer through the CPCI bus.

[0013] (2) Multi-channel analog output: The host computer sends digital signals to the FPGA via the CPCI bus. The FPGA then transmits the data to a high-precision DAC for digital-to-analog conversion. The converted analog signals are conditioned by a voltage follower and finally output to external devices via the SCSI interface.

[0014] (3) The FPGA is responsible for controlling the operation of the ADC and DAC to realize the acquisition, processing and output of analog data. At the same time, the FPGA is also responsible for data interaction with the CPCI bus to realize communication with the host computer.

[0015] (4) Interface compatibility: The CPCI bus interface enables high-speed data transmission with the host computer, and the SCSI interface enables flexible connection with external analog devices.

[0016] (5) Modular design; the motherboard is responsible for signal conditioning, AD / DA conversion and other functions, while the FPGA core board is responsible for data processing and control functions. The two are connected by a high-speed inter-board connector, which facilitates independent upgrades and maintenance. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0018] Figure 2 This is a schematic diagram of the FPGA core board of this utility model.

[0019] Figure 3 This is a schematic diagram of the analog input module of this utility model.

[0020] Figure 4 This is a schematic diagram of the single-ended input wiring of the analog quantity card of this utility model.

[0021] Figure 5 This is a schematic diagram of the differential input wiring of the analog quantity card of this utility model.

[0022] Figure 6 This is a schematic diagram of the analog output module of this utility model.

[0023] Figure 7 This is a schematic diagram of the single-ended output wiring of the analog quantity card of this utility model.

[0024] Figure 8 This is a schematic diagram of the differential output wiring of the analog quantity card of this utility model.

[0025] Figure 9 This is a schematic diagram of the power module of this utility model. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0027] like Figure 1 As shown, this embodiment provides a multi-channel analog input / output board, including an FPGA core board, an analog input module, an analog output module, a power supply module, a signal interface module, and a bus interface module. The FPGA core board is connected to the analog input module, the analog output module, the power supply module, and the bus interface module, respectively. The analog input module and the analog output module are both connected to the signal interface module.

[0028] The FPGA core board is built using the XC7A100T chip. Specifically, this embodiment uses the Shanghai Puzhi PZ-ARTIX7 series FPGA core board, model XC7A100T-2FFG484I. Figure 2 As shown, it includes functional modules such as clock crystal oscillator, DDR memory, SPI FLASH, reset, LED indicator, and power distribution. The FPGA core board is connected to the analog input module, analog output module, and power module through high-speed inter-board connectors, and is modularly connected to the bus interface through a PCI-to-PCIe bridge.

[0029] The signal interface module is used to input or output analog signals. It is implemented using a SCSI signal interface, which includes 16 analog input channels, 16 analog output channels, and a user-connected external analog reference ground. The 16 analog input channels include 8 single-ended and 8 differential analog input channels, and the 16 analog output channels include 8 single-ended and 8 differential analog output channels. The SCSI signal interface is connected to the analog input module and the analog output module.

[0030] The analog input module includes an analog input protection circuit, a resistor divider circuit, an analog switch circuit, a gain-controlled operational amplifier circuit, and an AD converter connected in sequence. After the input signal is protected by the analog input, it is connected to the voltage divider circuit. The divided analog signal is selected by the analog switch, and then the gain-controlled operational amplifier performs signal conditioning processing. The AD converter then converts the analog signal into a digital signal. The FPAG core board receives and buffers the data, and finally reports the data to the test equipment through the PCI bus. The test equipment then performs subsequent data processing.

[0031] like Figure 3 As shown, the analog input has 8 single-ended and 8 differential analog input channels. The single-ended and differential inputs are separate and do not interfere with each other. Simultaneous single-ended and differential inputs are supported. Two analog input channels share one analog input module, selected by an analog switch implemented using an ADG5436 single-pole double-throw switch. The resistor divider circuit divides the input analog signal by 1 / 4. The maximum analog input voltage is 40V; after voltage division, the input voltage is maintained within the allowable input voltage range of the ADC.

[0032] When using single-ended input, such as Figure 4 As shown, connect the ground terminal of the signal under test to the common ground (AGND) of the board, and the other terminal to the corresponding input port (VinX) of the board. For differential input, as shown... Figure 5 As shown, the two ends of the signal to be measured are connected to two differential input channels respectively, and the voltage difference between the two input terminals is measured.

[0033] The analog output module is a conditioning circuit consisting of a DAC digital-to-analog converter and a voltage follower. Analog data is sent to the FPGA core board via the PCI bus, and then sent by the FPGA core board to the DAC digital-to-analog converter to convert the digital signal into an analog signal before being sent out.

[0034] like Figure 6As shown, this embodiment has 8 single-ended and 8 differential ±10V analog outputs; the single-ended and differential outputs are separate and do not interfere with each other; single-ended and differential outputs can be output simultaneously. The analog signals output by the DAC digital-to-analog converter are all conditioned by a voltage follower composed of operational amplifier circuits. The voltage follower can provide a high-impedance input and a low-impedance output to subsequent circuits, reducing the influence of internal resistance on the differential circuit, thereby effectively isolating different parts of the circuit to prevent mutual interference; a self-resetting fuse is connected after the voltage follower to limit the maximum current to 10mA.

[0035] When using single-ended output, such as Figure 7 As shown, a voltage follower is connected after the DAC output signal. Connect one end of a wire to the corresponding output port (VinX) on the board, and the other end to the board's common ground (AGND). For differential output, as shown... Figure 8 As shown, two voltage followers are connected to the two ends of the DAC output differential signal. Connect the two ends of the device to the two differential output channels respectively, and connect the reference ground to the common ground (AGND) of the board.

[0036] The bus interface module is implemented using a CPCI interface, which enables PCI bus protocol communication. The PCI bus is connected to the FPGA core board via a PCI-to-PCIe bridge. The CPCI interface also provides 5V power to the motherboard.

[0037] like Figure 9 As shown, the power module includes a power switch circuit, a fuse, a reverse connection protection circuit, and a filter in sequence. Multiple DC / DC converters are connected after the filter. Power entering from the CPCI interface first passes through the power switch circuit, then through the resettable fuse and the reverse connection protection circuit, and then through the filter to meet electromagnetic compatibility requirements. It is then divided into six paths: one path connects to the system power circuit of the FPGA core board; two paths connect to the DC / DC converter, converting 5V to 3.3V and 1V respectively to provide input voltage for other circuits; two paths connect to the DC / DC converter, converting 5V to +15V and -15V respectively to provide power for the gain-controllable operational amplifier circuit, the AD converter, and the DAC digital-to-analog converter; and one path converts the 5V to 2.5V to provide a reference voltage.

[0038] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A multi-channel analog input / output board card, characterized by: It includes an FPGA core board, an analog input module, an analog output module, a power supply module, a signal interface module, and a bus interface module. The FPGA core board is connected to the analog input module, the analog output module, the power supply module, and the bus interface module, respectively. The analog input module and the analog output module are both connected to the signal interface module. The signal interface module adopts a SCSI signal interface, which includes multiple single-ended and multiple differential analog input channels, and multiple single-ended and multiple differential analog output channels. The analog input module includes an analog input protection circuit, a resistor voltage divider circuit, an analog switch circuit, a gain-controllable operational amplifier circuit, and an AD converter connected in sequence. The analog output module is a conditioning circuit consisting of a DAC digital-to-analog converter and a voltage follower.

2. The multi-channel analog input / output board card of claim 1, wherein: The FPGA core board is built with an XC7A100T chip. The FPGA core board is connected to the analog input module, analog output module and power module through a high-speed board-to-board connector, and is modularly connected to the bus interface through a PCI-to-PCIe bridge.

3. The multi-channel analog input / output board card of claim 1, wherein: A resettable fuse is connected after the voltage follower.

4. The multi-channel analog input / output board card of claim 2, wherein: The bus interface module is implemented using a CPCI interface. The PCI bus is connected to the FPGA core board using a PCI-to-PCIe bridge. The CPCI interface provides the operating power required by the board.

5. The multi-channel analog input / output board card of claim 4, wherein: The power module includes a power switch circuit, a fuse, a reverse connection protection circuit and a filter in sequence, and multiple DC / DC converters are connected after the filter. One DC / DC converter is connected to the power supply circuit of the FPGA core board; Two DC / DC converters convert 5V to 3.3V and 1V respectively to provide input voltage for other circuits; The two-channel DC / DC converter transforms 5V into +15V and -15V respectively to provide power to the gain-controlled operational amplifier circuit, AD converter and DAC digital-to-analog converter; One DC / DC converter converts 5V to 2.5V to provide a reference voltage.

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