Expansion board of data acquisition device

Abstract

The utility model discloses an expansion board of a data acquisition device, which belongs to the technical field of data acquisition and comprises an RS485 interface module, an Ethernet interface module, a 4G module, a LoRa module and a master control module. The RS485 interface module, the Ethernet interface module, the 4G module and the LoRa module are all connected with the main control module, and the main control module is connected with the substrate of the data acquisition device. Wherein the RS485 interface module comprises an RS485 serial port, a GDT protection circuit and a TVS protection circuit which are connected in sequence, and further comprises a self-recovery fuse arranged between the GDT protection circuit and the TVS protection circuit. The expansion board is used for being installed in a data acquisition device to be used as a master control gateway so as to solve the problem that networking and communication of an existing vibrating wire sensor acquisition device are inconvenient. Besides, the RS485 interface module is provided with a resettable fuse between the GDT protection circuit and the TVS protection circuit, a photoelectric isolation circuit is connected between the RS485 interface module and the master control module, and a power supply isolation circuit is connected between the RS485 interface module and the power supply module, so that the circuit protection effect is effectively improved.

Description

Technical Field

[0001] This utility model relates to the field of data acquisition technology, and in particular to an expansion board for a data acquisition device. Background Technology

[0002] A vibrating wire sensor is a common data acquisition device. It excites the vibrating wire in the vibrating wire sensor to vibrate and then measures the frequency of the vibration. Since the frequency of the vibrating wire has a specific relationship with the physical quantity it is subjected to (such as pressure, strain, displacement, temperature, etc.), the data acquisition device converts the measured frequency into the corresponding physical quantity value according to a predetermined mathematical model.

[0003] Existing vibrating wire sensor acquisition devices typically include a main control module, power supply module, vibration start-up module, vibration pickup module, vibrating wire sensor acquisition interface, and NTC resistance acquisition module, but lack a gateway module. Because vibrating wire sensor acquisition devices lack network connection management and protocol conversion functions, they require an external main control gateway to connect to a monitoring platform or other devices, making networking and communication methods cumbersome. Therefore, it is necessary to add an expansion board to enhance gateway functionality.

[0004] Furthermore, existing vibrating wire sensor acquisition devices generally have an RS485 interface. To ensure the normal operation and safety of the RS485 interface and the connected devices, the interface needs to be designed with lightning protection isolation. Lightning protection isolation design can improve the stability and reliability of the system, ensuring normal communication even when subjected to lightning strikes or other transient interferences, reducing the risk of equipment failure and data loss. Chinese patent CN 212435353 U proposes a lightning surge protection circuit for the RS485 port of an industrial IoT gateway. This protection circuit includes a primary protection circuit and a secondary protection circuit located between the RS485 serial port and the network card chip, as well as a serial port isolation power supply located between the RS485 serial port and the RS485 power supply chip. The primary protection circuit uses a ceramic gas discharge tube (GDT) capable of withstanding large surge currents, the secondary protection circuit uses a TVS diode to respond to surge voltages within a PS-level time range, and the power supply uses a DC / DC isolation module. When a surge such as lightning strikes, the TVS (Transient Voltage Suppressor) activates first, precisely controlling the instantaneous overvoltage to a certain level. If the surge current is large, the voltage across the terminals will increase until it drives the discharge of the pre-stage gas discharge tube, discharging the large current to ground. This circuit structure can effectively discharge surge current and absorb surge energy, improving the overall surge protection level and thus effectively protecting electronic components such as IoT gateway chips from damage caused by surge current.

[0005] However, since the aforementioned RS485 port surge protection circuit does not have protective devices such as fuses or circuit breakers, it can still damage the RS485 port or equipment when the current is too large and causes the GDT protection circuit (i.e., the primary protection circuit) and TVS protection circuit (i.e., the secondary protection circuit) to fail. The protection effect is not good, so it is necessary to improve the existing protection circuit. Utility Model Content

[0006] This invention proposes an expansion board for a data acquisition device, used as a main control gateway within the device to address the inconvenience of networking and communication in existing vibrating wire sensor acquisition devices. Furthermore, the expansion board's RS485 interface module incorporates a self-resetting fuse between the GDT and TVS protection circuits, forming a third-level protection circuit. When the circuit current is excessive, the fuse automatically trips and then automatically reconnects after a certain period, providing better protection for downstream circuits and addressing the issue of inadequate lightning protection in existing RS485 interface surge protection circuits.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0008] An expansion board for a data acquisition device includes an RS485 interface module, an Ethernet interface module, a 4G module, a LoRa module, and a main control module; the RS485 interface module, the Ethernet interface module, the 4G module, and the LoRa module are all connected to the main control module, and the main control module is connected to the base plate of the data acquisition device.

[0009] Furthermore, the RS485 interface module includes an RS485 serial port, a GDT protection circuit, and a TVS protection circuit connected in sequence, and also includes a self-resetting fuse disposed between the GDT protection circuit and the TVS protection circuit.

[0010] Furthermore, the RS485 interface module also includes a communication circuit located after the TVS protection circuit and connected to the TVS protection circuit, and the communication circuit is connected to the main control module by an opto-isolation circuit.

[0011] Furthermore, the opto-isolation circuit is provided with three optocouplers, and the communication circuit includes a communication chip. The RX, TX and EN terminals of the communication chip are connected to the RX, TX and EN terminals of the main control module respectively through the three optocouplers.

[0012] Furthermore, the RS485 interface module also includes an isolation power supply circuit connected between the RS485 serial port and the power supply module.

[0013] Furthermore, the expansion board also includes a rain gauge module connected to the main control module.

[0014] Furthermore, the expansion board also includes a debugging and programming interface module connected to the main control module.

[0015] Furthermore, the expansion board also includes a storage module connected to the main control module.

[0016] Furthermore, the expansion board also includes LED indicator lights connected to the main control module.

[0017] By adopting the above technical solution, this utility model has the following beneficial effects:

[0018] 1. The expansion board provided by this utility model is equipped with an RS485 interface module, an Ethernet interface module, a 4G module, a LoRa module, and a main control module, which has rich communication methods. It is used as a main control gateway when installed in a data acquisition device, so that the data acquisition device can be directly connected to the monitoring platform or other devices without the need for an external gateway. This can effectively solve the problem of inconvenient networking and communication of existing vibrating wire sensor acquisition devices.

[0019] 2. This utility model's RS485 interface module incorporates a self-resetting fuse between the GDT protection circuit and the TVS protection circuit, forming a third-level protection circuit. When the circuit current is excessive, the self-resetting fuse automatically trips and then automatically reconnects after a certain period, ensuring timely communication of the equipment. The self-resetting fuse provides better protection for downstream circuits. Furthermore, its automatic recovery function eliminates the need for manual intervention, reducing the workload of staff.

[0020] 3. The RS485 interface module of this invention is connected to the main control module by an opto-isolation circuit, and to the power supply module by an isolated power supply circuit, further improving the isolation effect and thus enhancing the safety of the RS485 interface module, the main control module, and the power supply module. Furthermore, the opto-isolation circuit uses three optocouplers, which is not only simple in structure but also lower in cost compared to existing isolation solutions. Attached Figure Description

[0021] Figure 1 This is a block diagram of the expansion plate proposed in this utility model;

[0022] Figure 2 This is a block diagram of the RS485 interface module proposed in this utility model;

[0023] Figure 3 The circuit diagram of the RS485 interface module proposed in this utility model is shown below.

[0024] Figure 4 This is the circuit schematic diagram of the main control module proposed in this utility model;

[0025] Figure 5 This is a circuit schematic diagram of the Ethernet interface module proposed in this utility model;

[0026] Figure 6 This is a circuit diagram of the power supply module proposed in this utility model;

[0027] Figure 7 This is a circuit diagram of the isolated power supply circuit proposed in this utility model;

[0028] Figure 8 This is a circuit schematic diagram of the storage module proposed in this utility model;

[0029] Figure 9 This is a circuit diagram of the rain gauge module proposed in this utility model; Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0031] Example

[0032] like Figure 1 As shown, an expansion board for a data acquisition device includes an RS485 interface module, an Ethernet interface module, a 4G module, a LoRa module, a main control module, a rain gauge module, a debugging and programming interface module, a storage module, and LED indicators. The RS485 interface module, Ethernet interface module, 4G module, LoRa module, rain gauge module, debugging and programming interface module, storage module, and LED indicators are all connected to the main control module, which is connected to the baseboard of the data acquisition device.

[0033] like Figure 2-3 As shown, the RS485 interface module includes an RS485 serial port, a GDT protection circuit, and a TVS protection circuit connected in sequence. It also includes a resettable fuse located between the GDT and TVS protection circuits. There are two resettable fuses (3), located on two separate lines. The model of the resettable fuse (3) is SMD1206P020TF.

[0034] A self-resetting fuse is added to the GDT and TVS protection circuits to form a third-level protection circuit. When the circuit current is too high, the self-resetting fuse automatically trips and then automatically reconnects after a certain period of time, ensuring timely communication of the equipment. The self-resetting fuse provides better protection for downstream circuits. In addition, its automatic recovery function requires no manual intervention, reducing the workload of staff.

[0035] The RS485 interface module also includes a communication circuit located after and connected to the TVS protection circuit. An opto-isolation circuit connects the communication circuit to the main control module. The opto-isolation circuit has three optocouplers. The communication circuit includes a communication chip, and the RX, TX, and EN terminals of the communication chip are connected to the RX, TX, and EN terminals of the main control module respectively via the three optocouplers. Figure 3 As shown, the communication chip is labeled U11 and its model number is SP3485EEN.

[0036] The RS485 interface module also includes an isolation power supply circuit connecting the RS485 serial port and the power supply module. For the circuit schematic of the isolation power supply circuit, please refer to [link to schematic]. Figure 7 .

[0037] The RS485 interface module of this invention is connected to the main control module by an opto-isolation circuit, and to the power supply module by an isolation power supply circuit, which further improves the isolation effect and thus enhances the safety of the RS485 interface module, the main control module, and the power supply module.

[0038] Furthermore, the opto-isolation circuit uses three optocouplers, which not only has a simple structure but also lower cost compared to existing isolation solutions. Existing isolation solutions generally use the ADUM1201 device (digital isolator), which has slightly better performance than optocoupler solutions, but its price is much higher. The ADUM1201 is a dual-channel isolation device, which only isolates the signal lines; the RS485 transmit / receive control pin 485EN is not isolated. If isolation of this pin is required, an additional ADUM1201 device is needed, which increases the cost.

[0039] The functions of some of the main components are briefly explained below.

[0040] The RS485 interface module is used to connect and communicate with the baseboard of the data acquisition device, smart sensors and other equipment.

[0041] The 4G module is used to provide 4G network access capabilities.

[0042] The LoRa module is used to provide LoRa communication capabilities.

[0043] The main control module is used to coordinate and control information from various hardware components, modules, and interfaces, and to perform gateway functions. Its circuit schematic is detailed in [link to schematic diagram]. Figure 4 The main control module is a microcontroller, model STM32F407VET6.

[0044] The Ethernet interface module is used to connect to data centers and monitoring platforms and exchange information. See the detailed circuit diagram below. Figure 5 .

[0045] The power supply module is used to supply power to the main control module and other hardware components. See the circuit schematic for details. Figure 6 .

[0046] The storage module is used to continuously record and store data from external sensors for more than two years. Its circuit schematic is detailed below. Figure 8 .

[0047] The rain gauge module provides a dedicated interface for rain gauges and can calculate the current rainfall information based on the read data. Its circuit diagram is shown below. Figure 9 As shown, it is actually an analog signal monitoring circuit.

[0048] The debugging and burning interface module is used for program debugging and program burning.

[0049] LED indicator lights are used to indicate the working status of the equipment.

[0050] The expansion board provided by this utility model is equipped with an RS485 interface module, an Ethernet interface module, a 4G module, a LoRa module, and a main control module, providing rich communication methods. It is used as a main control gateway when installed in a data acquisition device, allowing the data acquisition device to be directly connected to a monitoring platform or other devices without the need for an external gateway. This effectively solves the problem of inconvenient networking and communication in existing vibrating wire sensor acquisition devices.

[0051] The above description is a detailed description of the preferred embodiments of the present utility model. However, the embodiments are not intended to limit the scope of the patent application of the present utility model. All equivalent changes or modifications made under the technical spirit of the present utility model should fall within the patent scope covered by the present utility model.

Claims

1. An expansion board for a data acquisition device, characterized in that, It includes an RS485 interface module, an Ethernet interface module, a 4G module, a LoRa module, and a main control module; the RS485 interface module, Ethernet interface module, 4G module, and LoRa module are all connected to the main control module, and the main control module is connected to the base plate of the data acquisition device; the RS485 interface module includes an RS485 serial port, a GDT protection circuit, and a TVS protection circuit connected in sequence, and also includes a self-resetting fuse disposed between the GDT protection circuit and the TVS protection circuit.

2. The expansion board of the data acquisition device according to claim 1, characterized in that: The RS485 interface module also includes a communication circuit located after the TVS protection circuit and connected to the TVS protection circuit. The communication circuit is connected to the main control module by an opto-isolation circuit.

3. The expansion board of the data acquisition device according to claim 2, characterized in that: The opto-isolation circuit is equipped with three optocouplers, and the communication circuit includes a communication chip. The RX, TX, and EN terminals of the communication chip are connected to the RX, TX, and EN terminals of the main control module respectively through the three optocouplers.

4. The expansion board of the data acquisition device according to claim 3, characterized in that: The RS485 interface module also includes an isolation power supply circuit connected between the RS485 serial port and the power supply module.

5. The expansion board of the data acquisition device according to claim 1, characterized in that: The expansion board also includes a rain gauge module connected to the main control module.

6. The expansion board of the data acquisition device according to claim 1, characterized in that: The expansion board also includes a debugging and programming interface module connected to the main control module.

7. The expansion board of a data acquisition device according to claim 4, characterized in that: The expansion board also includes a storage module connected to the main control module.

8. The expansion board of the data acquisition device according to claim 1, characterized in that: The expansion board also includes LED indicator lights connected to the main control module.

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