CN113503985B

CN113503985B - Self-adaptive distributed intelligent measurement node of temperature sensor

Info

Publication number: CN113503985B
Application number: CN202110932347.XA
Authority: CN
Inventors: 陈非凡; 陈猛; 陈泽奇
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2021-08-13
Filing date: 2021-08-13
Publication date: 2022-05-03
Anticipated expiration: 2041-08-13
Also published as: CN113503985A

Abstract

The present disclosure relates to a temperature sensor adaptive distributed intelligent measurement node, the node has one or more terminal interfaces, each terminal interface can be connected with different types and different models of temperature sensors; the node can actively detect and automatically identify the connection relation between the temperature sensor and the sensor connecting component and the sensor parameters, and automatically configure the interface functional circuit, the analog signal processing circuit and the wiring loop detection circuit according to the connection relation; and automatically matching the corresponding temperature measurement conversion model according to the model of the temperature sensor so as to obtain the sensed temperature, interacting the sensed temperature to a communication link through a communication unit, and cooperatively working with other nodes with the same or different functions in the link to form a distributed intelligent measurement and control system. The embodiment of the disclosure can perform self-adaptive measurement on temperature sensors of different types and different models without changing any software and hardware, and has the characteristics of high adaptability, high flexibility, high efficiency and high expandability.

Description

Self-adaptive distributed intelligent measurement node of temperature sensor

Technical Field

The utility model relates to a measure technical field, especially relate to a temperature sensor self-adaptation distributed intelligence measurement node.

Background

Temperature monitoring is a very important link in the fields of national defense, industry, agriculture, scientific research and the like. The commonly used temperature sensors include resistance type temperature sensors and thermocouple sensors. The resistance temperature sensor is divided into a Resistance Temperature Detector (RTD) represented by PT100 and PT1000 and two major thermistor temperature sensors of NTC and PTC, and is manufactured into three lead forms of two, three and four wires according to the influence of lead resistance when in use; thermocouples are classified into various types such as S/R/B/N/K/E/J/T according to the difference in the manufacturing materials and the application fields.

Because the types and models of the temperature sensors are numerous, the traditional temperature monitoring nodes are generally developed aiming at specific sensors, and the field adaptability, flexibility and reusability are poor.

Disclosure of Invention

According to an aspect of the present disclosure, there is provided a temperature sensor adaptive distributed smart measurement node,

the node includes sensor coupling assembling, interface function circuit, wiring return circuit detection circuit, analog signal processing circuit, digital signal processing unit and communication unit, interface function circuit with sensor coupling assembling wiring return circuit detection circuit analog signal processing circuit reaches digital signal processing unit interconnect, digital signal processing unit with wiring return circuit detection circuit analog signal processing circuit communication unit interconnect, wherein:

the sensor connecting assembly comprises one or more same terminal interfaces, each terminal interface can be connected with various types of temperature sensors, and each terminal interface comprises a plurality of terminals;

the digital signal processing unit is used for communicating with an external communication link through the communication unit and controlling the interface function circuit, the wiring loop detection circuit and the analog signal processing circuit so as to:

actively detecting and automatically identifying the connection relationship between the temperature sensor and the sensor connecting assembly and the sensor parameters of the temperature sensor, wherein the connection relationship comprises the connection relationship between a lead of the sensor and a connecting terminal in the terminal interface, and the connecting terminal is one or more of a plurality of terminals of the terminal interface;

automatically configuring circuit parameters of one or more circuits among the interface function circuit, the analog signal processing circuit and the wiring loop detection circuit according to the connection relation and/or the sensor parameters;

automatically matching a temperature measurement conversion model corresponding to the temperature sensor according to the type of the temperature sensor;

and obtaining the sensing temperature of the temperature sensor according to the received sensing signal of the temperature sensor and the temperature measurement conversion model.

In a possible embodiment, the actively detecting and automatically identifying the connection relationship between the temperature sensor and the sensor connection assembly and the sensor parameter of the temperature sensor includes:

establishing a connection relationship between a first detection terminal of the terminal interface and a first input end of the analog signal processing circuit and a connection relationship between a second detection terminal of the terminal interface and a second input end of the analog signal processing circuit in sequence by using the interface function circuit, wherein the first detection terminal and the second detection terminal are one of a plurality of terminals of the terminal interface and are different from each other;

and determining the connection relation and the sensor parameters according to output signals corresponding to the first detection terminal and the second detection terminal which are paired at each time.

In a possible embodiment, the interface function circuit includes a multi-channel selection unit, a constant current source, a bias voltage source switching unit, a reference resistor, and a thermocouple cold junction compensation sensor, the analog signal processing circuit includes an adjustable gain amplifier, an analog-to-digital converter, a voltage reference source switching unit, and a voltage reference source, and circuit parameters of one or more of the interface function circuit, the analog signal processing circuit, and the wire loop detection circuit are automatically configured according to the connection relationship and/or the sensor parameters, and include at least one of:

automatically configuring channel selection signals of the multi-channel selection unit to perform at least one of: establishing a connection relation between the constant current source and a current input terminal, establishing a connection relation between the connection terminal and the input end of the adjustable gain amplifier according to a preset pairing mode, and establishing a connection relation between the reference resistor and a reference terminal, wherein the current input terminal and the reference terminal are any two of the terminals;

automatically configuring a first switching signal of the bias voltage source switching unit to apply a bias voltage source to any one of a plurality of terminals of the terminal interface;

automatically configuring a second switching signal of the voltage reference source switching unit to select a reference voltage for analog-to-digital conversion for the analog-to-digital converter, wherein the reference voltage is one of a divided voltage on the reference resistor or an output voltage of the voltage reference source;

automatically configuring a gain of the adjustable gain amplifier.

In one possible implementation, the temperature sensor includes a resistive temperature sensor including a two-wire resistive temperature sensor, a three-wire resistive temperature sensor, and a four-wire resistive temperature sensor, a thermocouple temperature sensor including S/R/B/N/K/E/J/T multiple types.

In a possible embodiment, if it is determined that the temperature sensor is a two-wire resistive temperature sensor according to the connection relationship and/or the sensor parameter, and the first end of the temperature sensor is connected to the first connection terminal of the terminal interface and the second end of the temperature sensor is connected to the second connection terminal of the terminal interface according to the connection relationship, the signal processing unit is further configured to:

automatically configuring the channel selection signal to establish a connection relationship between the constant current source and the first connection terminal, establish a connection relationship between the first connection terminal and a first input terminal of the adjustable gain amplifier, establish a connection relationship between the second connection terminal and a second input terminal of the adjustable gain amplifier, and establish a connection relationship between the second connection terminal and a first end of the reference resistor;

automatically configuring the second switching signal to establish a connection relationship between the first end of the reference resistor and a reference voltage input end of the analog-to-digital converter;

determining the resistance value of the temperature sensor according to the output of the analog-to-digital converter, the quantization digit of the analog-to-digital converter, the resistance value of the reference resistor and the gain of the adjustable gain amplifier;

automatically matching according to the type of the temperature sensor to obtain a corresponding temperature measurement conversion model, wherein the temperature measurement conversion model comprises a first resistance temperature mapping relation;

and obtaining the sensing temperature according to the resistance value of the temperature sensor and the temperature mapping relation of the first resistor.

In a possible embodiment, if it is determined that the temperature sensor is a three-wire resistive temperature sensor according to the connection relationship and/or the sensor parameter, and a first end of the temperature sensor is connected to the first connection terminal of the terminal interface, a second end of the temperature sensor is connected to the second connection terminal of the terminal interface, and a third end of the temperature sensor is connected to the third connection terminal of the terminal interface, the signal processing unit is further configured to:

automatically configuring the channel selection signal to establish a connection relationship between the constant current source and the first connection terminal and to establish a connection relationship between the third connection terminal and the first end of the reference resistor;

automatically configuring the channel selection signal to establish a connection relationship between the first connection terminal and a first input end of the adjustable gain amplifier according to the preset pairing mode, and to establish a connection relationship between the second connection terminal and a second input end of the adjustable gain amplifier to obtain a first output of the analog-to-digital converter;

automatically configuring the channel selection signal to establish a connection relationship between the second connection terminal and the first input end of the adjustable gain amplifier according to the preset pairing mode, and establishing a connection relationship between the third connection terminal and the second input end of the adjustable gain amplifier to obtain a second output of the analog-to-digital converter;

determining the resistance value of the temperature sensor according to the first output, the second output, the quantization digit of the analog-to-digital converter, the resistance value of the reference resistor and the gain of the adjustable gain amplifier;

automatically matching according to the type of the temperature sensor to obtain a corresponding temperature measurement conversion model, wherein the temperature measurement conversion model comprises a second resistance temperature mapping relation;

and obtaining the sensing temperature according to the resistance value of the temperature sensor and the temperature mapping relation of the second resistor.

In a possible embodiment, if it is determined that the temperature sensor is a four-wire resistive temperature sensor according to the connection relationship and/or the sensor parameter, and the first end of the temperature sensor is connected to the first connection terminal of the terminal interface, the second end of the temperature sensor is connected to the second connection terminal of the terminal interface, the third end of the temperature sensor is connected to the third connection terminal of the terminal interface, and the fourth end of the temperature sensor is connected to the fourth connection terminal of the terminal interface, the signal processing unit is further configured to:

automatically configuring the channel selection signal to establish a connection relationship between the constant current source and the first connection terminal, establish a connection relationship between the second connection terminal and the first input terminal of the adjustable gain amplifier, establish a connection relationship between the third connection terminal and the second input terminal of the adjustable gain amplifier, and establish a connection relationship between the fourth connection terminal and the first end of the reference resistor according to the preset pairing mode;

automatically matching according to the type of the temperature sensor to obtain a corresponding temperature measurement conversion model, wherein the temperature measurement conversion model comprises a third resistance temperature mapping relation;

and obtaining the sensing temperature according to the resistance value of the temperature sensor and the temperature mapping relation of the third resistor.

In a possible embodiment, if it is determined that the temperature sensor is a thermocouple temperature sensor according to the connection relationship and/or the sensor parameter, and the first end of the temperature sensor is connected to the first connection terminal of the terminal interface and the second end of the temperature sensor is connected to the second connection terminal of the terminal interface according to the connection relationship, the signal processing unit is further configured to:

automatically configuring the first switching signal to apply a bias voltage source to the first connection terminal or the second connection terminal;

automatically configuring the channel selection signal to establish a connection relationship between the first connection terminal and a first input end of the adjustable gain amplifier, and to establish a connection relationship between the second connection terminal and a second input end of the adjustable gain amplifier;

automatically configuring the second switching signal to establish a connection relation between the voltage reference source and a reference voltage input end of the analog-to-digital converter;

determining a first voltage according to the output of the analog-to-digital converter, the quantization bit number of the analog-to-digital converter, the voltage of the voltage reference source and the gain of the adjustable gain amplifier;

automatically matching according to the type of the temperature sensor to obtain a corresponding temperature measurement conversion model, wherein the temperature measurement conversion model comprises a temperature-voltage mapping relation and a voltage-temperature mapping relation;

determining a second voltage according to the temperature of the thermocouple cold end compensation sensor and by utilizing the temperature-voltage mapping relation;

and obtaining the sensing temperature according to the sum of the first voltage and the second voltage and the voltage-temperature mapping relation.

In one possible implementation, the node further comprises:

the bus power supply is used for supplying power to the nodes;

the communication unit includes:

the measurement and control network device is connected with the signal processing unit and used for forming a distributed temperature measurement system through networking with the plurality of nodes, outputting the sensing temperature and receiving the model of the temperature sensor;

and the network terminal component is connected with the measurement and control network device and the bus power supply and is used for communicating with an external communication link through a network cable and obtaining power supply.

In a possible implementation, the interface function circuit includes a multi-channel selection unit, a constant current source, a bias voltage source switching unit, a reference resistor, a thermocouple cold junction compensation sensor, and a temperature equalization chamber, the analog signal processing circuit includes an adjustable gain amplifier, an analog-to-digital converter, a voltage reference source switching unit, a voltage reference source, the communication unit includes a measurement and control network device, a network terminal assembly, the node further includes a bus power supply, the digital signal processing unit includes a signal processor, each terminal interface includes a first terminal, a second terminal, a third terminal, a fourth terminal, the multi-channel selection unit includes a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, and an eighth switch, the wiring loop detection circuit includes a first detection resistor, a second detection resistor, a third terminal, and a fourth terminal, and a third terminal, a fourth switch, a second detection circuit, a second circuit, a second detection circuit, a second circuit, a second detection resistor, a first detection switch, a second detection switch, wherein,

the first terminal is connected to the first end of the first switch and the first end of the second switch, the second end of the first switch is connected to the output end of the constant current source,

the second terminal is connected to the first output terminal of the bias voltage source switching unit, the first terminal of the third switch, and the first terminal of the fourth switch, the input terminal of the bias voltage source switching unit is connected to the bias voltage source,

the third terminal is connected to a first terminal of the fifth switch and a first terminal of the sixth switch,

the fourth terminal is connected to the first terminal of the seventh switch, the first terminal of the eighth switch, and the second output terminal of the bias voltage source switching unit,

the second end of the second switch, the second end of the third switch and the second end of the fifth switch are connected to the first input end of the adjustable gain amplifier,

a second terminal of the fourth switch, a second terminal of the sixth switch, and a second terminal of the seventh switch are connected to a second input terminal of the adjustable gain amplifier,

a second terminal of the eighth switch and a first terminal of the reference resistor are connected to a first input terminal of the voltage reference source switching unit,

the second input end of the voltage reference source switching unit is connected to the voltage reference source, the output end of the voltage reference source switching unit is connected to the reference voltage input end of the analog-to-digital converter,

the first end of the first detection resistor is used for receiving a power supply voltage, the second end of the first detection resistor is connected to the first end of the first detection switch, the second end of the first detection switch is connected to the first input end of the adjustable gain amplifier, the first end of the second detection resistor is grounded, the second end of the second detection resistor is connected to the first end of the second detection switch, and the second end of the second detection switch is connected to the second input end of the adjustable gain amplifier,

the output end of the adjustable gain amplifier is connected with the input end of the analog-to-digital converter, the output end of the analog-to-digital converter is connected with the input end of the signal processor,

the signal processor is connected with the measurement and control network device,

the measurement and control network device communicates with an external communication link through the network terminal assembly, the network cable,

and the bus power supply is used for taking power from a network cable to supply power to the node.

According to an aspect of the present disclosure, there is provided a temperature measurement system, including:

a plurality of the temperature sensor self-adaptive distributed intelligent measurement nodes;

the configuration device is used for configuring the model of the connected temperature sensor for each temperature sensor self-adaptive distributed intelligent measurement node;

the power supply device is used for supplying power to each temperature sensor self-adaptive distributed intelligent measurement node;

the temperature sensor self-adaptive distributed intelligent measurement nodes, the configuration device and the power supply device are connected in a networking mode through network cables.

The self-adaptive distributed intelligent measurement node of the temperature sensor provided by the embodiment of the disclosure can control the interface function circuit, the wiring loop detection circuit and the analog signal processing circuit under the condition that the temperature sensor is connected to the terminal interface, so as to: actively detecting and automatically identifying the connection relation between the temperature sensor and the sensor connecting component and the sensor parameters of the temperature sensor; automatically configuring circuit parameters of one or more circuits among the interface function circuit, the analog signal processing circuit and the wiring loop detection circuit according to the connection relation and/or the sensor parameters; automatically matching a temperature measurement conversion model corresponding to the temperature sensor according to the type of the temperature sensor; the sensing temperature of the temperature sensor is obtained according to the received sensing signal of the temperature sensor and the temperature measurement conversion model, the temperature measurement can be completed in a self-adaptive mode aiming at different types of sensors, and the method has the advantages of being high in adaptability, flexibility and efficiency.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. Other features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the disclosure.

Fig. 1 shows a block diagram of a temperature sensor adaptive distributed smart measurement node according to an embodiment of the disclosure.

Fig. 2 shows a schematic diagram of a temperature sensor adaptive distributed smart measurement node according to an embodiment of the present disclosure.

FIG. 3 shows a schematic diagram of a temperature sensor adaptive distributed smart measurement node accessing and measuring a two-wire system resistive temperature sensor according to an embodiment of the present disclosure.

FIG. 4 illustrates a schematic diagram of a temperature sensor adaptive distributed smart measurement node accessing and measuring a three-wire system resistive temperature sensor according to an embodiment of the disclosure.

FIG. 5 shows a schematic diagram of a temperature sensor adaptive distributed smart measurement node accessing and measuring a four wire system resistive temperature sensor according to an embodiment of the present disclosure.

FIG. 6 shows a schematic diagram of a temperature sensor adaptive distributed smart measurement node accessing and measuring a thermocouple temperature sensor according to an embodiment of the present disclosure.

FIG. 7 shows a schematic diagram of a thermometry system according to an embodiment of the present disclosure.

Detailed Description

Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers can indicate functionally identical or similar elements. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

In the description of the present disclosure, it is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, as used herein, refer to an orientation or positional relationship indicated in the drawings, which is solely for the purpose of facilitating the description and simplifying the description, and does not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and, therefore, should not be taken as limiting the present disclosure.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present disclosure, "a plurality" means two or more unless specifically limited otherwise.

In the present disclosure, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integral; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present disclosure can be understood as a specific case by a person of ordinary skill in the art.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the term "at least one" herein means any one of a plurality or any combination of at least two of a plurality, for example, including at least one of A, B, C, and may mean including any one or more elements selected from the group consisting of A, B and C.

Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a better understanding of the present disclosure. It will be understood by those skilled in the art that the present disclosure may be practiced without some of these specific details. In some instances, methods, means, elements and circuits that are well known to those skilled in the art have not been described in detail so as not to obscure the present disclosure.

As can be known from introduction to the background art, because the types and models of the temperature sensors are numerous, the conventional temperature monitoring nodes are generally developed for specific sensors, and have poor field adaptability, flexibility and reusability, for example, when an application scene is changed in the related art, if the type of the sensor to be accessed by the temperature monitoring node changes, the internal circuit of the temperature monitoring node needs to be adjusted, and a control program needs to be modified, and for different temperature sensors in different scenes, the software and hardware structures need to be adjusted according to changes in environmental requirements.

The self-adaptive distributed intelligent measurement node of the temperature sensor in the embodiment of the disclosure considers the adaptability and the use convenience of temperature sensors of different types and models, can be directly accessed and automatically adapted to the temperature measurement of two/three/four-wire resistance type temperature sensors of different models and thermocouples of different types (such as S/R/B/N/K/E/J/T and the like) on the premise of not changing software and hardware of the node, can expand the number of measurement channels as required, and has higher expandability.

The temperature sensor adaptive distributed intelligent measurement node of the embodiment of the disclosure can be applied to various fields such as national defense, industry, agriculture and scientific research, and the application field of the temperature sensor adaptive distributed intelligent measurement node of the embodiment of the disclosure is not limited by the embodiment of the disclosure.

Referring to fig. 1, fig. 1 shows a block diagram of a temperature sensor adaptive distributed intelligent measurement node according to an embodiment of the present disclosure.

As shown in fig. 1, the node includes a sensor connecting assembly 100, an interface function circuit 200, a wiring loop detection circuit 9, an analog signal processing circuit 400, a digital signal processing unit 500 and a communication unit 900, the interface function circuit 200 is connected to the sensor connecting assembly 100, the wiring loop detection circuit 9, the analog signal processing circuit 400 and the digital signal processing unit 500, and the digital signal processing unit 500 is connected to the wiring loop detection circuit 9, the analog signal processing circuit 400 and the communication unit 900, wherein:

the sensor connecting assembly 100 comprises one or more same terminal interfaces 1, each terminal interface 1 can be connected with multiple types of temperature sensors, and each terminal interface 1 comprises multiple terminals;

the digital signal processing unit 500 is configured to communicate with an external communication link through the communication unit 900, and control the interface function circuit 200, the wiring loop detection circuit 9, and the analog signal processing circuit 400 to:

actively detecting and automatically identifying the connection relationship between the temperature sensor and the sensor connection assembly 100 and the sensor parameters of the temperature sensor, wherein the connection relationship comprises the connection relationship between lead wires of the sensor and connection terminals in the terminal interface 1, and the connection terminals are one or more of a plurality of terminals in the terminal interface 1;

automatically configuring circuit parameters of one or more circuits among the interface function circuit 200, the analog signal processing circuit 400 and the wiring loop detection circuit 9 according to the connection relation and/or the sensor parameters;

The number of the interfaces of the terminal interface 1 in the sensor interface assembly is not limited in the embodiments of the present disclosure, and those skilled in the art may set the number according to actual needs, for example, the sensor interface assembly may include 1, 2, or more terminal interfaces 1.

The number of terminals included in the terminal interface 1 is not limited in the embodiment of the present disclosure, and those skilled in the art can set the terminal interface according to actual needs, for example, each terminal interface 1 may include 4 terminals or other numbers of terminals.

In the embodiment of the present disclosure, the connection relationship between the temperature sensor and the terminal interface 1 and the sensor parameters may be determined in various ways, and a corresponding path is selected according to the connection relationship to connect the connection terminal to the analog signal processing circuit 400 in various ways, which is not limited in the embodiment of the present disclosure.

The embodiment of the present disclosure does not limit the specific implementation manners of the interface function circuit 200, the wiring loop detection circuit 9, the analog signal processing circuit 400, the digital signal processing unit 500, and the communication unit 900, and those skilled in the art can determine the implementation manners according to actual situations and needs.

The following provides an exemplary description of possible implementations of the temperature sensor adaptive distributed intelligent measurement node according to the embodiments of the present disclosure.

Referring to fig. 2, fig. 2 shows a schematic diagram of a temperature sensor adaptive distributed intelligent measurement node according to an embodiment of the present disclosure.

It should be understood that each example of the embodiment of the present disclosure is exemplarily described by setting the number of terminals of the terminal interface 1 to 4, but the embodiment of the present disclosure is not limited thereto, and a person skilled in the art may set the number of terminals of the interface as needed.

In one example, as shown in fig. 2, the temperature sensor adaptive distributed smart measurement node may include a terminal interface 1 to access a temperature sensor, for example, the terminal interface 1 includes 4 terminals (a first terminal a, a second terminal B, a third terminal C, and a fourth terminal D), and the temperature sensor adaptive distributed smart measurement node may access a one-way two/three/four-wire resistive temperature sensor or 1-3-way S/R/B/N/K/E/J/T thermocouple to perform adaptive measurement of temperature.

In a possible implementation, as shown in fig. 2, the interface function circuit 200 may include a multi-channel selection unit 8, a constant current source 2, a bias voltage source 4, a bias voltage source switching unit 5, a reference resistor 3, a thermocouple cold end compensation sensor 6, and a temperature equalization chamber 7, the analog signal processing circuit 400 may include an adjustable gain amplifier 10, an analog-to-digital converter 11, a voltage reference source switching unit 12, and a voltage reference source 13, the communication unit 900 may include a measurement and control network device 15 and a network terminal component 16, and the node may further include a bus power supply 17. Illustratively, the measurement and control network device 15 may communicate with an external communication link through the network terminal assembly 16 and the network cable, and the bus power supply 17 is configured to take power from the network cable to supply power to the node.

In one example, as shown in fig. 2, a measurement and control network device 15 is connected to the digital signal processing unit (e.g., the signal processor 14) and configured to form a distributed temperature measurement system with a plurality of nodes, output the sensed temperature, and receive the model of the temperature sensor, and a network terminal assembly 16 connected to the measurement and control network device 15 and the bus power supply 17 may be configured to communicate with the outside world through a network cable and obtain power supply. The communication unit 900 is exemplified by the measurement and control network device 15 and the network terminal assembly 16 in the embodiment of the present disclosure, it should be understood that the embodiment of the present disclosure is not limited thereto, and those skilled in the art can implement the communication unit 900 in an appropriate manner according to actual situations and needs as long as it can implement communication with an external communication link. The implementation manner of the external communication link is not limited in the embodiments of the present disclosure, and the external communication link may include a plurality of nodes that are networked with the current node or other networked devices, and implement communication in a wireless transmission manner such as WiFi, ZigBee, and mobile communication network (4G, 5G, etc.), and certainly, may also implement communication in a wired manner such as various industrial field buses and network cables, and thus, the embodiments of the present disclosure are not limited.

Illustratively, as shown in FIG. 2, the network terminal assembly 16 may include a T_pAnd T_nOn one hand, the two interface terminals can enable a plurality of nodes to be connected end to end through network cables (such as distributed intelligent measurement and control network cables) to form a distributed intelligent measurement and control network, and on the other hand, the measurement and control network device 15 can be directly accessed into the distributed intelligent measurement and control network.

Illustratively, the measurement and control network device 15 may perform bidirectional information interaction with the signal processor 14, on one hand, the sensor model information may be configured to the signal processor 14 on line, and on the other hand, the temperature information given by the signal processor 14 may be acquired and distributed to the distributed intelligent measurement and control network for sharing by other nodes.

For example, a user may write in the model or other information of the temperature sensor through an external control device (e.g., an upper computer), and transmit the information to the temperature sensor adaptive distributed intelligent measurement node through a network cable, for example, the information may be transmitted to the measurement and control network device 15, and transmit the information to the signal processing unit 500 (e.g., the signal processor 14) through the measurement and control network device 15, and of course, the user may also obtain the temperature information or other intermediate parameters obtained by the temperature sensor adaptive distributed intelligent measurement node through the network cable, which is not limited in this embodiment of the disclosure.

In one possible implementation, as shown in fig. 2, the digital signal processing unit 500 may include the signal processor 14, and the signal processing unit may be a processing component including, but not limited to, a single processor, or discrete components, or a combination of a processor and discrete components. The processor may comprise a controller in an electronic device having the functionality to execute instructions, which may be implemented in any suitable manner, for example, by one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), tunable logic devices (PLDs), field-tunable gate arrays (FPGAs), controllers, micro-controllers, microprocessors, or other electronic components. Within the processor, the executable instructions may be executed by hardware circuits such as logic gates, switches, Application Specific Integrated Circuits (ASICs), tunable logic controllers, and embedded microcontrollers.

In a possible implementation, as shown in fig. 2, each terminal interface 1 may include a first terminal a, a second terminal B, a third terminal C, and a fourth terminal D, the multi-channel selection unit 8 may include a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a fifth switch S5, a sixth switch S6, a seventh switch S7, and an eighth switch S8, and the wire loop detection circuit 9 may include a first detection resistor R1, a second detection resistor R2, a first detection switch K1, and a second detection switch K2.

It should be understood that fig. 2 shows a case that the number of terminals of the terminal interface 1 may be 4, the number of selection switches of the multi-channel selection unit 8 is 8, etc., however, these specific examples are only for better describing the temperature sensor adaptive distributed intelligent measurement node of the embodiment of the present disclosure, and should not be considered as limitations to the embodiment of the present disclosure, in other embodiments, the number of terminals may also be any other number, the number of switches may be configured as required (for example, multiple sets of the second switch S2 to the seventh switch S7 may be configured to implement access of multiple temperature sensors), and the multi-channel selection unit 8 may also be implemented in any other manner, such as a multiplexer, etc., without limiting the embodiment of the present disclosure.

It should be understood that the embodiment of the present disclosure is exemplified by the wire loop detection circuit 9 including the first detection resistor R1, the second detection resistor R2, the first detection switch K1, and the second detection switch K2, however, the embodiment of the present disclosure is not limited thereto, and in other embodiments, the wire loop detection circuit 9 may have other implementations, for example, the first detection resistor R1 and the second detection resistor R2 may be replaced by a micro-current source, or implemented in other ways.

In one example, as shown in fig. 2, the voltage reference source switching unit 12 may include two independent switches, one end of the first switch (which may be used as a first input end of the voltage reference source switching unit 12) is connected to the non-grounded side of the reference resistor 3, one end of the second switch (which may be used as a second input end of the voltage reference source switching unit 12) is connected to the voltage reference source 13, and the other ends of the two switches (which may be used as an output end of the voltage reference source switching unit 12) are both connected to the external reference end "V" of the analog-to-digital converter 11_ref"pin (i.e., reference voltage input).

Illustratively, each switch of the embodiments of the present disclosure may be implemented by using a Transistor, for example, a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), an Insulated Gate Bipolar Transistor (IGBT), wherein the Transistor may be implemented based on silicon carbide (SiC) or gallium nitride (GaN) to improve performance. Of course, the embodiments of the present disclosure do not limit the types of the switches, and those skilled in the art may implement any type of switches.

In one possible implementation, as shown in fig. 2, the first terminal a is connected to the first terminal of the first switch S1 and the first terminal of the second switch S2, the second terminal of the first switch S1 is connected to the output terminal of the constant current source 2, the second terminal B is connected to the first output terminal of the bias voltage source switching unit 5, the first terminal of the third switch S3 and the first terminal of the fourth switch S4, the input terminal of the bias voltage source switching unit 5 is connected to the bias voltage source 4, the third terminal C is connected to the first terminal of the fifth switch S5 and the first terminal of the sixth switch S6, the fourth terminal D is connected to the first terminal of the seventh switch S7, the first terminal of the eighth switch S8 and the second output terminal of the bias voltage source switching unit 5, the second terminal of the second switch S2, the first terminal of the second switch S3526, and the second terminal of the second switch S8, A second end of the third switch S3, a second end of the fifth switch S5 are connected to a first input end of the adjustable gain amplifier 10 (which may be a first input end of the analog signal processing circuit 400), a second end of the fourth switch S4, a second end of the sixth switch S6 and a second end of the seventh switch S7 are connected to a second input end of the adjustable gain amplifier 10 (which may be a second input end of the analog signal processing circuit 400), a second end of the eighth switch S8 and a first end of the reference resistor 3 are connected to a first input end of the voltage reference source switching unit 12, a second input end of the voltage reference source switching unit 12 is connected to the voltage reference source 13, an output end of the voltage reference source switching unit 12 is connected to a reference voltage input end of the analog-to-digital converter 11, a first end of the first detection resistor R1 is used for receiving a power supply voltage, the second end of the first detecting resistor R1 is connected to the first end of the first detecting switch K1, the second end of the first detecting switch K1 is connected to the first input end of the adjustable gain amplifier 10, the first end of the second detecting resistor R2 is grounded, the second end of the second detecting resistor R2 is connected to the first end of the second detecting switch K2, the second end of the second detecting switch K2 is connected to the second input end of the adjustable gain amplifier 10, the output end of the adjustable gain amplifier 10 is connected to the input end of the analog-to-digital converter 11, the output end of the analog-to-digital converter 11 is connected to the input end of the signal processor 14, and the signal processor 14 is connected to the measurement and control network device 15.

Taking the adaptive distributed intelligent measurement node of the temperature sensor shown in fig. 1 and fig. 2 as an example, the embodiment of the present disclosure can automatically control circuits such as the interface function circuit 200, the wiring loop detection circuit 9, and the analog signal processing circuit 400 by using the digital signal processing unit 500, and can adaptively configure and complete adaptive measurement of temperature sensors including resistance-type temperature sensors (which may include various types, each type may include two-wire system, three-wire system, and four-wire system), thermocouple temperature sensors (such as S/R/B/N/K/E/J/T, etc.) and the like without changing software and hardware thereof, and a distributed monitoring network can be automatically constructed by using a plurality of nodes. On one hand, the intelligent self-adaptive networking measurement problem of temperature sensors of different types and models in an industrial field is solved, and on the other hand, the problems of repeated design and development of software and hardware of measurement conversion circuits of the temperature sensors are also solved.

It should be noted that the implementation of the node shown in fig. 2 may be changed as needed, a unit, a device, and a circuit may be added, or other implementations may be used for replacement, and various implementations that may implement the functions of each circuit are within the scope of the present disclosure.

It should be noted that various implementations of the various devices, circuits, etc. of the node shown in fig. 2 are possible, and the disclosed embodiments will be exemplified below with respect to possible implementations.

The control manner of each circuit of the node is exemplarily described below, so that the node can adaptively configure and perform adaptive measurement on temperature sensors including types of resistive temperature sensors (which may include various types, each of which may include a two-wire system, a three-wire system, and a four-wire system), thermocouple temperature sensors (such as S/R/B/N/K/E/J/T, etc.), and the like.

The following describes an exemplary possible implementation manner for actively detecting and automatically recognizing the connection relationship between the temperature sensor and the sensor connection assembly 100 and the sensor parameters of the temperature sensor.

In a possible embodiment, the actively detecting and automatically identifying the connection relationship between the temperature sensor and the sensor connection assembly 100 and the sensor parameters of the temperature sensor may include:

sequentially establishing a connection relationship between a first detection terminal of the terminal interface 1 and a first input terminal of the analog signal processing circuit 400 and a connection relationship between a second detection terminal of the terminal interface 1 and a second input terminal of the analog signal processing circuit 400 by using the interface function circuit 200, wherein the first detection terminal and the second detection terminal are both one of a plurality of terminals of the terminal interface 1 and are different from each other;

In one example, sensor parameters in embodiments of the present disclosure may include resistance, voltage, sensor type (resistive, thermocouple, etc.), sensor wire system (two-wire, three-wire, four-wire), and the like.

In the embodiment of the present disclosure, the interface function circuit 200 is used to sequentially establish a connection relationship between the first detection terminal of the terminal interface 1 and the first input terminal of the analog signal processing circuit 400 and a connection relationship between the second detection terminal of the terminal interface 1 and the second input terminal of the analog signal processing circuit 400, and the connection relationship and the sensor parameters can be quickly and accurately determined according to output signals corresponding to the first detection terminal and the second detection terminal paired at each time, so as to facilitate subsequent adaptive temperature measurement.

Illustratively, the interface function circuit 200 of the embodiment of the present disclosure may include the multi-channel selection unit 8 shown in fig. 2, and of course, the multi-channel selection unit 8 may be implemented in various ways, for example, the multi-channel selection unit 8 may include a plurality of switches as shown in fig. 2, which are turned on or off according to the control signal to implement the selection of the path; for example, the multi-channel selection unit 8 may also include a multiplexer MUX to gate the corresponding channel according to the control signal, or the function of the multi-channel selection unit 8 may be implemented in other ways. The control signal of the multi-channel selection unit 8 of the embodiment of the present disclosure may be set in the signal processing unit, or the multi-channel selection unit 8 may be configured with control logic in advance, for example, the multi-channel selection unit 8 may also be provided with a logic device to implement channel selection and switching.

For example, whether the control signal output by the signal processing unit or the control logic pre-stored in the multi-channel selecting unit 8 is utilized, the connection relationship between the first detection terminal of the terminal interface 1 and the first input terminal of the analog signal processing circuit 400 and the connection relationship between the second detection terminal of the terminal interface 1 and the second input terminal of the analog signal processing circuit 400 can be sequentially established. For example, when the temperature sensor is connected, the signal processing unit may output a control signal to sequentially establish a connection relationship between the first detection terminal of the terminal interface 1 and the first input terminal of the analog signal processing circuit 400 and a connection relationship between the second detection terminal of the terminal interface 1 and the second input terminal of the analog signal processing circuit 400, or the multi-channel selection unit 8 may sequentially establish a connection relationship between the first detection terminal of the terminal interface 1 and the first input terminal of the analog signal processing circuit 400 and a connection relationship between the second detection terminal of the terminal interface 1 and the second input terminal of the analog signal processing circuit 400 according to a control logic.

For example, as shown in fig. 2, the terminal interface 1 may include a first terminal a, a second terminal B, a third terminal C, a fourth terminal D, illustratively, for the first time: the first terminal a, the second terminal B may be connected to the analog signal processing circuit 400 as a first detection terminal and a second detection terminal; and (3) for the second time: the first terminal a and the third terminal C may be connected to the analog signal processing circuit 400 as a first probe terminal and a second probe terminal; and thirdly: the first terminal a, the fourth terminal D may be connected to the analog signal processing circuit 400 as a first detection terminal and a second detection terminal, and so on; if the terminal interface 1 also comprises another number of terminals, the attempt may be continued, for example, the mth time: the i-th terminal and the j-th terminal are connected to the analog signal processing circuit 400 as a first probe terminal and a second probe terminal until all the terminals are traversed, wherein i, j, and M are integers.

The digital signal processing unit 500 may determine the connection relationship and the sensor parameter according to the output signals corresponding to the first detection terminal and the second detection terminal paired at each time, for example, may determine according to the amplitude of the output signal, which is described in the following exemplary description.

In one example, when two probing terminals are connected to two input terminals of the analog signal processing circuit 400, the analog signal processing circuit 400 forms a loop with the two probing terminals, and if the two probing terminals are connected to lead terminals of the temperature sensor, the analog signal processing circuit 400 outputs an output signal of a first amplitude; if the two detection terminals are not connected to the temperature sensor, the analog signal processing circuit 400 outputs an output signal with a second amplitude, the digital signal processing unit 500 according to the embodiment of the disclosure can determine the terminals connected to the temperature sensor according to the amplitude of the output signal of the analog signal processing circuit 400 (for example, the output signal of the analog signal processing circuit 400 is converted into a digital quantity for determination), and the connection relationship can be accurately determined in a traversal manner, so as to achieve interface adaptive determination and automatic detection.

The following is an exemplary description with specific examples.

In one possible implementation, as shown in fig. 2, the analog signal processing circuit 400 may include an adjustable gain amplifier 10(PGA), and the first input terminal of the adjustable gain amplifier 10 may be a first input terminal of the analog signal processing circuit 400, and the second input terminal of the adjustable gain amplifier 10 may be a second input terminal of the analog signal processing circuit 400.

In one example, as shown in fig. 2, the first detecting resistor R1 may be a pull-up resistor, the second detecting resistor R2 may be a pull-down resistor, the first detecting resistor R1 and the first detecting switch are connected between the positive power supply terminal VCC and the "+" terminal of the differential input of the PGA 10, the second detecting resistor R2 and the second detecting switch are connected between the negative power supply terminal GND and the "-" terminal of the differential input of the PGA 10, and the resistance of the pull-up resistor and the pull-down resistor may be set to be much larger than the resistance of the resistance temperature sensor to be measured and the thermocouple lead. In one example, when the + and-poles (the first input terminal and the second input terminal) of the adjustable gain amplifier 10 form a current loop through the multi-channel selection unit 8 and the connected sensor, the voltage division between the + and-poles is very small, the ADC11 will output a small digital quantity (an output signal with a first amplitude) to the signal processor 14, and if the voltage division between the + and-poles is close to VCC in the off state, the ADC11 will output a large digital quantity (an output signal with a second amplitude, for example, in the full scale) to the signal processor 14, so as to detect the connection relationship between any two detection terminals in the terminal interface 1.

In one example, when the temperature sensor is normally connected, the wire system of the resistance temperature sensor and the actual access channel of the thermocouple correspond to the connection relationship between different terminals, and the relationship can be made into a reference table, so that the wire system of the resistance temperature sensor and the access channel of the thermocouple can be detected before measurement starts, parameters of some sensors can be actively identified, and early warning or alarming can be performed on disconnection faults of the sensor in the measurement process.

The following describes an exemplary connection relationship, and a connectivity test is performed between each pair of probing terminals of the terminal interface 1, so as to automatically detect a wire system of the resistance temperature sensor and an access channel condition of the thermocouple.

TABLE 1

For example, in order to access the two/three/four wire resistive temperature sensor through the terminal interface 1, in order to detect the wire system accessed to the resistive temperature sensor, taking fig. 2 as an example, if the number of the terminals included in the terminal interface 1 is 4 (for example, the first terminal a, the second terminal B, the third terminal C, and the fourth terminal D), the connection relationship between the terminal pairs, such as the first terminal a, the second terminal B, the first terminal a, the third terminal C, and the first terminal a, and the fourth terminal D, can be detected sequentially. When the resistance temperature sensor is normally connected, the connection relationship of the terminal interface 1 corresponding to different wire systems is shown in table 1, wherein 1 and 0 respectively represent connection or disconnection between two terminals. According to table 1, the wiring system of the resistance type temperature sensor can be detected before the start of measurement, and the disconnection fault of the sensor can be early warned and alarmed in the measurement process.

TABLE 2

For example, still taking an example that the terminal interface 1 includes 4 terminals as an example for description, the terminal interface 1 may simultaneously access 1 to 3 different types of thermocouples, and in order to detect which of the actual access channels of the thermocouples are, the connection relationships between the first terminal a and the second terminal B, between the second terminal B and the third terminal C, and between the third terminal C and the fourth terminal D may be successively detected. The connection relationship between the different terminals is compared with the thermocouple access channel condition as shown in table 2. According to the table 2, the condition of the thermocouple access channel can be detected before the measurement is started, and the thermocouple disconnection fault can be pre-warned and alarmed in the measurement process.

For example, taking a terminal interface 1 with four terminals as an example, the terminal interface 1 may simultaneously access 3 thermocouples, for example, the thermocouple 1 is connected between the first terminal a and the second terminal B, the thermocouple 2 is connected between the second terminal B and the third terminal C, and the thermocouple 3 is connected between the third terminal C and the fourth terminal D.

In the embodiment of the present disclosure, sensor parameters such as resistance and voltage may be obtained under various conditions, and in some conditions, parameters such as sensor type and sensor wiring system may also be obtained, for example, referring to tables 1 and 2, in a case where only a single temperature sensor is connected, connection relationships of the sensors are different, and therefore, a type, a wiring system, and the like of the temperature sensor may be determined according to a determined connection relationship and a correspondence relationship between the connection relationship and the temperature sensor type shown in tables 1 and 2, for example, if the determined connection relationship is that the sensor is only connected to the first terminal a and the fourth terminal D, it may be determined that the temperature sensor is a two-wire system resistance type temperature sensor; if the determined connection relationship is that the sensor is connected to only any one of the first terminal a and the second terminal B, the second terminal B and the third terminal C, and the third terminal C and the fourth terminal D, the temperature sensor may be determined to be a thermocouple.

Of course, the sensor parameters of the temperature sensor in the embodiment of the present disclosure may also include other parameters, and other embodiments may also be used to determine the sensor parameters, which is not limited in the embodiment of the present disclosure.

Through the above description, the embodiment of the present disclosure may successively determine the connection relationship between the terminals to determine the type of the accessed temperature sensor, further, according to the preset corresponding relationship (e.g., table 1 and table 2), the type, the wire system, and other parameters of the accessed temperature sensor may be determined according to the determined connection relationship, the type may include the resistance temperature sensor and the thermocouple temperature sensor, the wire system may be the wire system (e.g., two/three/four wire system) of the resistance temperature sensor, and of course, the access channel of the thermocouple temperature sensor may also be determined.

The adaptive measurement of the node is exemplified by a resistance temperature sensor and a thermocouple temperature sensor.

In a possible embodiment, as shown in fig. 2, the interface function circuit 200 may include a multi-channel selection unit 8, a constant current source 2, a bias voltage source 4, a bias voltage source switching unit 5, a reference resistor 3, a thermocouple cold junction compensation sensor 6, and a temperature equalization chamber 7, the analog signal processing circuit 400 includes an adjustable gain amplifier 10, an analog-to-digital converter 11, a voltage reference source switching unit 12, and a voltage reference source 13, and circuit parameters of one or more of the interface function circuit 200, the analog signal processing circuit 400, and the wire loop detection circuit 9 are automatically configured according to the connection relationship and/or the sensor parameters, and may include at least one of:

automatically configuring the channel selection signal of the multi-channel selection unit 8 to perform at least one of the following operations: establishing a connection relationship between the constant current source 2 and a current input terminal, establishing a connection relationship between the connection terminal and an input end of the adjustable gain amplifier 10 according to a preset pairing mode, and establishing a connection relationship between the reference resistor 3 and a reference terminal, wherein the current input terminal and the reference terminal are any two of the plurality of terminals;

automatically configuring a first switching signal of the bias voltage source switching unit 5 to apply a bias voltage source 4 to any one of a plurality of terminals of the terminal interface 1;

automatically configuring a second switching signal of the voltage reference source switching unit 12 to select a reference voltage for analog-to-digital conversion for the analog-to-digital converter 11, where the reference voltage is one of a divided voltage on the reference resistor 3 or an output voltage of the voltage reference source 13;

the gain of the adjustable gain amplifier 10 is automatically configured.

In one example, when a two/three/four-wire resistive temperature sensor is connected, the embodiment of the present disclosure may measure the resistance by using a proportional resistance measurement method, so that the embodiment of the present disclosure can eliminate the influence of the accuracy and stability of the constant current source 2 on the measurement. When 1-3 paths of thermocouple sensors are connected, the measuring circuit automatically detects the connection channel and the signal amplitude, automatically configures bias voltage and proper amplification factor for the connected thermocouples, and the multiple paths of thermocouples finish measurement by adopting a time-sharing one-by-one method.

The adaptive measurement of various temperature sensors is exemplarily illustrated based on the schematic diagram of the temperature sensor adaptive distributed intelligent measurement node shown in fig. 2.

Referring to fig. 3, fig. 3 is a schematic diagram illustrating a temperature sensor adaptive distributed smart measurement node accessing and measuring a two-wire resistive temperature sensor according to an embodiment of the present disclosure.

In a possible embodiment, as shown in fig. 3, if it is determined that the temperature sensor is a two-wire resistance temperature sensor according to the connection relationship and/or the sensor parameter, and a first end (e.g. lead 1) of the temperature sensor is connected to a first connection terminal (e.g. first terminal a) of the terminal interface 1 and a second end (e.g. lead 2) of the temperature sensor is connected to a second connection terminal (e.g. fourth terminal D) of the terminal interface 1 according to the connection relationship, as shown in fig. 3, the signal processing unit may further be configured to:

the channel selection signal is automatically configured to establish the connection relationship of the constant current source 2 and the first connection terminal, thereby inputting an excitation current to the first connection terminal.

Establishing a connection relationship between the first connection terminal and a first input end of the adjustable gain amplifier 10, a connection relationship between the second connection terminal and a second input end of the adjustable gain amplifier 10, and a connection relationship between the second connection terminal and a first end of the reference resistor 3 according to the preset pairing mode;

automatically configuring the second switching signal to establish a connection relationship between the first end of the reference resistor 3 and the reference voltage input end of the analog-to-digital converter 11, so as to provide a reference voltage for the analog-to-digital converter 11;

determining the resistance value of the temperature sensor according to the output of the analog-to-digital converter 11, the quantization digit of the analog-to-digital converter 11, the resistance value of the reference resistor 3 and the gain of the adjustable gain amplifier 10;

For example, as shown in fig. 3, when measuring the temperature of the resistance temperature sensor, the embodiment of the present disclosure may close the first switch S1 and the eighth switch S8 switch in the multi-channel selection unit 8, in this case, the excitation current generated by the constant current source 2 enters the first terminal a in the terminal interface 1 and flows through the resistance temperature sensor, the fourth terminal D in the terminal interface 1, and the reference resistor 3 in sequence and finally enters the ground, thereby forming the main loop of the measurement circuit; the voltage reference source switching unit 12 can be controlled to gate the actual voltage on the reference resistor 3 to the reference voltage input end of the analog-to-digital converter (ADC)11 as the reference voltage for analog-to-digital conversion, the multi-channel selection unit 8 can be controlled to connect two connection terminals (such as the first terminal a and the fourth terminal D) in the terminal interface 1, which are connected to the temperature sensor, to the differential input end of the PGA 10, the differential voltage is amplified by the PGA 10 and then input to the ADC11 to complete digital conversion, and the digital quantity given by the ADC is converted into the resistance value of the resistance temperature sensor by the signal processor 14, thereby forming a complete resistance proportional measurement structure.

In one example, as shown in fig. 3, lead 1 and lead 2 of the two-wire resistance temperature sensor are respectively connected to the first terminal a and the fourth terminal D in the terminal interface 1, the first switch S1, the second switch S2, the seventh switch S7 and the eighth switch S8 in the multi-channel selection unit 8 are closed, and the rest are opened, so that the first terminal a and the fourth terminal D in the terminal interface 1 are connected to the differential input end of the PGA 10, and the ADC11 performs digital conversion; the resistance value of the two-wire resistance type temperature sensor to be measured is R_xThe reference resistor 3 has a resistance value of R_refThe gain of PGA 10 is A, the quantization bit number of ADC11 is N, and if the ADC11 measures the conversion output value D_outThen the resistance R of the two-wire resistance type temperature sensor to be measured_xThe measurement equation of (a) is shown in equation 1:

n, A may be set as required, and the embodiments of the present disclosure are not limited thereto.

For example, the signal processor 14 can calculate the resistance value R of the two-wire resistance temperature sensor according to the above measurement equation_xDetermining a first resistance temperature mapping relation according to the type of the temperature sensor; obtaining the sensing temperature according to the resistance value of the temperature sensor and the temperature mapping relation of the first resistor, and obtaining a further resistance value R of the sensing temperature according to a built-in general temperature sensor information model_xAnd converted into temperature information. It should be noted that different types of resistive temperature sensors may have differentThe same resistance temperature mapping relationship, the resistance temperature mapping relationship of each wire-made resistance temperature sensor of the same signal can be the same.

For example, the model of the temperature sensor may be obtained through external input, for example, when the temperature sensor is connected, a user may configure the model of the connected temperature sensor; of course, the model can also be obtained by an active detection mode.

The embodiment of the present disclosure does not limit the specific implementation manner of the first resistance-temperature mapping relationship, and the first resistance-temperature mapping relationship may be pre-stored in the storage module of the signal processor 14 or in the storage module of the temperature sensor adaptive distributed intelligent measurement node, and is called by the signal processor 14 to implement resistance-temperature conversion. In one example, a memory module may include a computer-readable storage medium, which may be a tangible device that may hold and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but not limited to, an electronic memory device, a magnetic memory device, an optical memory device, an electromagnetic memory device, a semiconductor memory device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a Static Random Access Memory (SRAM), a programmable read-only memory (PROM), a portable compact disc read-only memory (CD-ROM), a Digital Versatile Disc (DVD), a memory stick, a floppy disk, a mechanical coding device, a punch card or in-groove projection arrangement such as with instructions stored thereon, and any suitable combination of the foregoing.

Referring to fig. 4, fig. 4 shows a schematic diagram of a temperature sensor adaptive distributed smart measurement node accessing and measuring a three-wire resistive temperature sensor according to an embodiment of the present disclosure.

In a possible embodiment, as shown in fig. 4, if it is determined that the temperature sensor is a three-wire resistance temperature sensor according to the connection relationship and/or the sensor parameter, and a first end (e.g. lead 1) of the temperature sensor is connected to a first connection terminal (e.g. first terminal a) of the terminal interface 1, a second end (e.g. lead 2) of the temperature sensor is connected to a second connection terminal (e.g. second terminal B) of the terminal interface 1, and a third end (e.g. lead 3) of the temperature sensor is connected to a third connection terminal (e.g. fourth terminal D) of the terminal interface 1 according to the connection relationship, the signal processing unit may be further configured to:

automatically configuring the channel selection signal to establish a connection relationship of the constant current source 2 and the first connection terminal;

establishing a connection relation between the third connection terminal and the first end of the reference resistor 3;

automatically configuring the second switching signal to establish a connection relationship between the first end of the reference resistor 3 and the reference voltage input end of the analog-to-digital converter 11;

automatically configuring the channel selection signal to establish a connection relationship between the first connection terminal and the first input terminal of the adjustable gain amplifier 10 according to the preset pairing mode, and to establish a connection relationship between the second connection terminal and the second input terminal of the adjustable gain amplifier 10, so as to obtain a first output of the analog-to-digital converter 11;

automatically configuring the channel selection signal to establish a connection relationship between the second connection terminal and the first input terminal of the adjustable gain amplifier 10 according to the preset pairing mode, and establishing a connection relationship between the third connection terminal and the second input terminal of the adjustable gain amplifier 10 to obtain a second output of the analog-to-digital converter 11;

determining the resistance value of the temperature sensor according to the first output, the second output, the quantization digit of the analog-to-digital converter 11, the resistance value of the reference resistor 3 and the gain of the adjustable gain amplifier 10;

In one example, as shown in fig. 4, according to the determined connection relationship, the lead 1, the lead 2 and the lead 3 of the three-wire resistance temperature sensor are respectively connected with the first terminal a, the second terminal B and the fourth terminal D in the terminal interface 1, and the embodiment of the disclosure can automatically eliminate the influence of the lead resistance on the measurement result through two differential measurements. In one example, for the first time, the first switch S1, the second switch S2, the fourth switch S4 and the eighth switch S8 in the multi-channel selection unit 8 may be controlled to be closed, the excitation current is input to the first connection terminal (the first terminal a), the first terminal a and the second terminal B in the terminal interface 1 are connected to the differential input terminal of the PGA 10, and the digital conversion is completed by the ADC11, and the output value (the first output) of the ADC11 is D_out1The sum of the resistance Rx to be measured and the lead resistance r is measured; in the second operation, the first switch S1, the third switch S3, the seventh switch S7 and the eighth switch S8 in the multi-channel selection unit 8 can be controlled to be closed, the second terminal B and the fourth terminal D in the terminal interface 1 are connected to the differential input end of the PGA 10, and the digital conversion is completed by the ADC11, and the output value (second output) of the ADC11 is D_out2The lead resistance r is measured. The difference between the differential voltage obtained by the two measurements can offset the influence of the lead resistance r on the measurement.

In one example, let the resistance of the three-wire resistive temperature sensor to be measured be R_xThe reference resistor 3 has a resistance value of R_refWhen the gain of the PGA 10 is A and the quantization digit of the ADC11 is N, the resistance R of the three-wire resistance type temperature sensor to be measured is_xThe measurement equation of (c) can be as shown in equation 2:

in one example, the signal processor 14 can calculate the resistance value R of the three-wire resistive temperature sensor to be measured according to the above measurement equation_xTo realize the signal processor 14 according to the firstThe output, the second output, the quantization bit number of the analog-to-digital converter 11, the resistance value of the reference resistor 3, and the gain of the adjustable gain amplifier 10 determine the resistance value of the temperature sensor, and of course, the above formula is exemplary, and in other embodiments, the above formula may be adjusted as needed, and thus, the embodiment of the present disclosure is not limited. Under the condition that the resistance value of the temperature sensor is obtained and the second resistance temperature mapping relation is determined according to the type of the temperature sensor, the embodiment of the disclosure can obtain the sensing temperature according to the resistance value of the temperature sensor and the second resistance temperature mapping relation and further obtain the resistance value R of the sensing temperature according to a built-in general temperature sensor information model_xAnd converted into temperature information.

The embodiment of the present disclosure does not limit the specific implementation manner of the second resistance-temperature mapping relationship, and the second resistance-temperature mapping relationship may be pre-stored in the storage module of the signal processor 14 or in the storage module of the temperature sensor adaptive distributed intelligent measurement node, and is called by the signal processor 14 to implement resistance-temperature conversion. It should be noted that, if the three-wire resistance temperature sensor and the two-wire resistance temperature sensor are of the same type, the first resistance temperature mapping relationship and the second resistance temperature mapping relationship may be the same, and if they are of different types, they may be different.

Referring to fig. 5, fig. 5 is a schematic diagram illustrating a temperature sensor adaptive distributed smart measurement node accessing and measuring a four-wire system resistance temperature sensor according to an embodiment of the present disclosure.

In one possible embodiment, as shown in fig. 5, if the temperature sensor is determined to be a four-wire resistance temperature sensor according to the connection relationship and/or the sensor parameter, and, a first end (such as a lead 1) of the temperature sensor is connected to a first connection terminal (such as a first terminal A) of the terminal interface 1 according to the connection relation, a second end (e.g., lead 2) of the temperature sensor is connected to a second connection terminal (e.g., second terminal B) of the terminal interface 1, a third terminal (e.g. lead 3) of the temperature sensor is connected to a third connection terminal (e.g. third terminal C) of the terminal interface 1, a fourth terminal (e.g., a lead 4) of the temperature sensor is connected to a fourth connection terminal (e.g., a fourth terminal D) of the terminal interface 1, and the signal processing unit is further configured to:

automatically configuring the channel selection signal to establish a connection relationship between the constant current source 2 and the first connection terminal, a connection relationship between the second connection terminal and the first input terminal of the adjustable gain amplifier 10, a connection relationship between the third connection terminal and the second input terminal of the adjustable gain amplifier 10, and a connection relationship between the fourth connection terminal and the first end of the reference resistor 3;

In one example, as shown in fig. 4, the lead 1, the lead 2, the lead 3, and the lead 4 of the four-wire resistive temperature sensor are respectively connected to the first terminal a, the second terminal B, the third terminal C, and the fourth terminal D in the terminal interface 1, the embodiment of the disclosure may control the first switch S1, the third switch S3, the sixth switch S6, and the eighth switch S8 in the multi-channel selection unit 8 to be closed, and the second terminal B and the third terminal C in the terminal interface 1 are connected to the differential input end of the PGA 10, so that the influence of the lead resistance can be automatically eliminated (because there is almost no current on the lead 2 and the lead 3), and the ADC11 performs the digital conversion.

In one example, let the resistance of the four-wire resistance temperature sensor to be measured be R_xThe reference resistor 3 has a resistance value of R_refThe gain of PGA 10 is A, the quantization bit number of ADC11 is N, and if the ADC11 measures the conversion output value D_outThen the resistance R of the four-wire resistance type temperature sensor to be measured_xThe measurement equation of (c) can be as shown in equation 3:

in one example, the signal processor 14 may determine the resistance value R of the temperature sensor according to the measurement equation, based on the output of the analog-to-digital converter 11, the quantization accuracy of the analog-to-digital converter 11, the resistance value of the reference resistor 3, and the gain of the adjustable gain amplifier 10_xAnd determining a third resistor temperature mapping relation according to the type of the temperature sensor, and obtaining the sensed temperature according to the resistance value of the temperature sensor and the third resistor temperature mapping relation.

The embodiment of the present disclosure does not limit the specific implementation manner of the third resistance-temperature mapping relationship, and the third resistance-temperature mapping relationship may be pre-stored in the storage module of the signal processor 14 or in the storage module of the temperature sensor adaptive distributed intelligent measurement node, and is called by the signal processor 14 to implement resistance-temperature conversion. It should be noted that, if the four-wire system resistance temperature sensor is of the same type as the three-wire system resistance temperature sensor and the two-wire system resistance temperature sensor, the third resistance temperature mapping relationship, the first resistance temperature mapping relationship, and the second resistance temperature mapping relationship may be the same, or may be different if they are of different types.

The following describes an exemplary resistance-temperature mapping relationship with specific examples.

Illustratively, for a resistance temperature sensor, taking a platinum resistance temperature sensor PT100 as an example, the "resistance- > temperature" conversion curves of PT100 produced by different temperature standards are different, but a general equation can be adopted for fitting, the PT100 of each temperature standard is marked as an independent model, and the coefficients are stored in a storage module corresponding to a set of equation coefficients (corresponding to different resistance temperature mapping relations).

For example, the general "resistance- > temperature" conversion equation T ═ h (r) of the metal thermal resistance type temperature sensor can be expressed as formula 4:

wherein R represents the resistance determined in the above manner, A, B, k_iRepresenting the coefficients, n representing the highest order of the polynomial fit made, R₀Represents the resistance value of an exemplary resistive temperature sensor at 0 deg.C, R for PT100₀Is 100 omega.

Illustratively, the temperature standards of the PT100 are numerous, and three temperature standards of ITS-90, IEC-751 and JISC-1604 are taken as examples, and a design scheme of the coefficients of the "resistance- > temperature" conversion equation of the PT100 with different temperature standards is given, as shown in Table 3. Other temperature criteria PT100 may also be populated into this table to obtain corresponding resistance-temperature maps, illustratively, each temperature criteria corresponding to a row of coefficients in table 3. In addition, the same method can be adopted for the resistive temperature sensors such as PT10, PT500, PT2000, CU50, and CU100, and the coefficients of the "resistance- > temperature" conversion equation are stored in table 3, and the different temperature standards of each resistive temperature sensor are regarded as independent models.

TABLE 3

In one example, table 3 and the above general "resistance- > temperature" conversion equation T ═ h (r) can be combined to map the resistance temperature to each resistance.

The manner in which the temperature of the thermocouple temperature sensor is measured is described below by way of example.

Referring to fig. 6, fig. 6 shows a schematic diagram of a temperature sensor adaptive distributed smart measurement node accessing and measuring a thermocouple temperature sensor according to an embodiment of the present disclosure.

In a possible embodiment, as shown in fig. 6, if it is determined that the temperature sensor is a thermocouple temperature sensor according to the connection relationship and/or the sensor parameter, and the first end of the temperature sensor is connected to the first connection terminal of the terminal interface 1 and the second end of the temperature sensor is connected to the second connection terminal of the terminal interface 1 according to the connection relationship, the signal processing unit may be further configured to:

automatically configuring the first switching signal to apply a bias voltage source 4 to the first connection terminal or the second connection terminal;

automatically configuring the channel selection signal to establish a connection relationship between the first connection terminal and a first input terminal of the adjustable gain amplifier 10, and to establish a connection relationship between the second connection terminal and a second input terminal of the adjustable gain amplifier 10;

automatically configuring the second switching signal to establish a connection relationship between the voltage reference source 13 and a reference voltage input end of the analog-to-digital converter 11;

determining a first voltage according to the output of the analog-to-digital converter 11, the quantization bit number of the analog-to-digital converter 11, the voltage of the voltage reference source 13 and the gain of the adjustable gain amplifier 10;

determining a second voltage according to the temperature of the thermocouple cold end compensation sensor 6 and by utilizing the temperature-voltage mapping relation;

In an example, as shown in fig. 6, taking an example that the terminal interface 1 includes four a/B/C/D terminals as an example for description, the embodiments of the present disclosure may measure 1-3 paths of thermocouple sensors without changing software and hardware of nodes.

In one example, as shown in fig. 6, when a thermocouple is connected, any two adjacent terminals in the terminal interface 1 can be used as access channels of the thermocouple, so that three thermocouple access channels, namely an a (+) B (-) channel, a B (+) C (-) channel and a C (+) D (-) channel, can be formed, and can realize direct access and adaptive measurement of 1-3 paths of thermocouples of types, such as S/R/B/N/K/E/J/T, and the like, wherein each channel allows thermocouples of different types to be connected simultaneously, and for example, each channel can be measured sequentially during measurement.

In one example, as shown in fig. 6, in terms of the circuit configuration, when the thermocouple access is confirmed according to the connection relation, the embodiment of the disclosure may control the first switch S1 and the eighth switch S8 in the multi-channel selection unit 8 to remain open, and when each thermocouple is measured, the bias voltage source switching unit 5 applies the bias voltage of the bias voltage source 4 to one end of the thermocouple, so that the common mode voltage of the positive and negative electrodes of the thermocouple is about half of the supply voltage of the PGA 10, thereby ensuring that the subsequent circuit can gain the thermocouple tiny voltage signal by higher times, the terminals to which the thermocouples are connected may be connected to the differential inputs of the PGA 10 via a multi-channel selection unit 8, the digital conversion is performed by the ADC11 after amplification by a suitable factor by the PGA 10, which, for example, the constant output voltage of the voltage reference source 13 can be selected as the reference voltage for the analog/digital conversion of the ADC11 by the voltage reference source switching unit 12.

In one example, as shown in FIG. 5, at the time of temperature measurement, it is assumed that the constant output voltage of the voltage reference source 13 is V_refThe gain of PGA 10 is A, the quantization bit number of ADC11 is N, and if the ADC11 measures the conversion output value D_outThe cold end voltage difference E (T, T) of the thermocouple to be measured_n) The measurement equation of (c) can be as in equation 5:

in one example, thermocouple cold end compensation sensor 6 may be coupled to signal processor 14 assuming thermocouple cold end compensation sensor 6 outputs a cold end actual temperature T_nThe signal processor 14 may determine a temperature-voltage mapping relationship (e.g., "temperature->Voltage "conversion equation E ═ f (t)), then the signal processor 14 passes" temperature->Voltage "conversion equation E ═ f (T) can obtain equivalent thermoelectric potential E (T) of thermocouple cold junction temperature relative to 0 degree centigrade_nT0), i.e., the temperature-voltage mapping relationship, can be expressed as equation 6:

E(T_n,T₀)＝f(T_n) Equation 6

In one example, the equivalent thermoelectric potential E (T, T0) of a thermocouple at 0 degrees celsius for the cold end can be expressed as equation 7 according to the thermocouple mid-temperature law:

E(T,T₀)＝E(T,T_n)+E(T_n,T₀) Equation 7

In one example, the signal processor 14 may obtain a voltage-temperature mapping relationship (for example, "voltage- > temperature" conversion equation T ═ g (e)) through the model of the thermocouple, and obtain an actual temperature T of the measurement end of the thermocouple through "voltage- > temperature" conversion equation T ═ g (e)), that is, the voltage-temperature mapping relationship may be as shown in equation 8:

T＝g(E(T,T₀) Equation 8)

In one example, in the general temperature sensor information model built in the signal processor 14, the "temperature- > voltage" conversion equation E ═ f (T) and the "voltage- > temperature" conversion equation T ═ g (E) of multiple types of thermocouples, such as S/R/B/N/K/E/J/T, may both adopt general equations, and each type of thermocouple corresponds to a set of equation coefficients, so that only thermocouple model information of an access channel needs to be configured online, that is, the corresponding equation coefficients may be automatically called to complete information processing of thermocouple measurement signals of the channel, and temperature information to be measured is obtained.

The following describes an exemplary voltage-temperature mapping relationship and a temperature-voltage mapping relationship.

For example, for various types of standard thermocouples such as S/R/B/N/K/E/J/T, the "temperature- > voltage" conversion equation E ═ f (T) and the "voltage- > temperature" conversion equation T ═ g (E) can be fitted by using general equations.

For example, the general "temperature- > voltage" conversion equation E ═ f (t) can be expressed as equation 9:

wherein c represents the coefficient, n represents the highest order of the polynomial fit, a₀，a₁，a₂Both represent coefficients.

For example, the general "voltage- > temperature" conversion equation T ═ g (e) can be expressed as equation 10:

wherein d represents a coefficient and n represents the highest order of the polynomial fit.

For example, taking the most common type K thermocouple as an example, a specific design value of the transformation equation coefficient is given, and equation coefficients of other types of thermocouples can be filled in the same table, wherein each row in the table represents the equation coefficient of one temperature interval of one type of thermocouple. The corresponding rows can be automatically retrieved from the table and the coefficients of the measurement conversion equation can be obtained according to the measurement result by only configuring the type information of the thermocouple sensor accessed into each channel on line, so that the intelligent self-adaptive information processing is carried out on the thermocouple actually accessed, and the sensor signal is converted into the temperature information.

Table 4 shows a general "temperature- > voltage" conversion equation E ═ f (t) coefficient table, and from table 4 and the general "temperature- > voltage" conversion equation E ═ f (t), a temperature-voltage mapping relationship of each type of thermocouple can be obtained.

TABLE 4

Table 5 shows a table of coefficients of the "voltage- > temperature" conversion equation T ═ g (e), and a voltage-temperature mapping relationship of each type of thermocouple can be obtained according to table 5 and the common "voltage- > temperature" conversion equation T ═ g (e).

TABLE 5

The above description of the mapping relationships is exemplary and should not be construed as limiting the embodiments of the present disclosure, and in other embodiments, the temperature-voltage mapping relationships and the voltage-temperature mapping relationships may have other forms, and different types and kinds of temperature sensors may have other forms of mapping relationships, which may be set by a person skilled in the art as needed.

The following description is provided for exemplary implementation of each device, and it should be understood that the selection of each device in the embodiments of the present disclosure is not limited, and the selection of the devices may be determined according to actual situations or needs, and the description of each device or component indicates the functions thereof, and the functions of the modules may be implemented by a general-purpose processor, or may be built by a technician using a basic component. As integrated circuits have evolved, some chips may have more than one function, and the various features described in the disclosed embodiments may be partially integrated into a single chip, such embodiments also being possible and protected by this patent.

In one example, the terminal interface 1 may be directly soldered to the circuit board of the node using a 3.81 mm-spaced flange-type four-port female socket, and the sensor leads are connected to a mating plug and inserted into the flange female socket and fastened by screws, such as an LC1M-3.81 type four-port flange female socket.

In an example, the constant current source 2 may provide an excitation current for a two/three/four-wire resistive temperature sensor, and the embodiment of the present disclosure may employ a proportional measurement structure, so that neither the accuracy nor the stability of the constant current source 2 affects the accurate measurement of the resistive temperature sensor, and for example, a TL431 or other chips may be used to build a circuit of the constant current source 2, and for a resistive temperature sensor such as PT100 or PT1000, the self-heating excitation current may be set to 100 uA.

In an example, the resistance value of the reference resistor 3 may be greater than that of the resistance temperature sensor to be measured, and the voltage generated by the constant current source 2 flowing through the reference resistor 3 may be within the limit range of the ADC external reference voltage. For example, for the measurement of PT100 and PT1000 temperature sensors, the maximum value of the resistance to be measured is about 2.1k Ω, the excitation current of the constant current source 2 may be 100uA, and the reference resistor 3 may be a low temperature drift metal thin film resistor of 22k Ω, which may provide a reference voltage of 2.2V for the ADC. Theoretically, the type and model of the resistance-type temperature sensor which can be accessed to the node for measurement are not limited, and only the reference resistor 3 and the microampere-level constant current source 2 need to be selected according to needs.

In an example, the bias voltage source 4 may provide a rough dc bias signal for the thermocouple sensor, and does not need to be precise, so that the bias signal can be obtained by voltage division from the bus power supply 17 by using a resistance voltage division principle, and of course, a separate voltage source may be provided or implemented by other ways, which is not limited in the embodiment of the present disclosure.

In one example, the bias voltage source switching unit 5 and the voltage reference source switching unit 12 may be implemented by one two-way electronic switch.

In one example, the thermocouple cold end compensation sensor 6 can adopt an on-board patch type high-precision digital temperature sensor, for example, a sensor with the temperature in the range of-20 ℃ to 100 ℃ and the typical temperature measurement precision value superior to 0.1 ℃ can be selected to meet the requirement of high-precision compensation of cold ends of various thermocouples.

In one example, the temperature equalizing chamber 7 can be directly welded on the node circuit by a metal shielding cover, and the cold end terminal and the thermocouple cold end compensation temperature sensor are sealed in a small space for the purpose of temperature equalization.

In one example, the multi-channel selection unit 8 may employ an 8-switch multiplexer chip.

In an example, the wiring loop detection circuit 9 may be implemented by using a two-way electronic switch and two large resistors or micro current sources, and the selected resistor should be much larger than the maximum resistance of the resistance temperature sensor to be detected.

In one example, the PGA 10 may be a differential amplifier, for example, a differential input terminal having a high input impedance, and the positive and negative electrodes of the differential input terminal have rail-to-rail input ranges, for example, a differential amplifier having an adjustable gain multiple of 1 to 128 times may be selected.

In one example, the ADC11 may be a Sigma-Delta ADC, which has high acquisition precision, usually has a bit number of 16 or 24 bits, and has a digital filtering function, so as to have a good suppression effect on power frequency interference.

In one example, the voltage reference source 13 may provide a reference voltage for the ADC, which may be selected according to actual needs.

In one example, the signal processor 14 may be a controller having functionality to execute instructions, which may be implemented in any suitable manner, e.g., by one or more Application Specific Integrated Circuits (ASICs), digital signal processors 14 (DSPs), Digital Signal Processing Devices (DSPDs), tunable logic devices (PLDs), field tunable gate arrays (FPGAs), controllers, micro-controllers, microprocessors, or other electronic components. In one example, the signal processor 14 may serve as a control unit of other devices, for example, the signal processor 14 may be logically connected to the bias voltage source switching unit 5, the thermocouple cold junction compensation sensor 6, the multi-channel selection unit 8, the wiring loop detection circuit 9, the adjustable gain amplifier 10, the analog-to-digital converter 11, and the voltage reference source switching unit 12, and may control these components to implement corresponding measurement tasks; the signal processor 14 is internally provided with a general temperature sensor informatization model, such as a resistance- > temperature conversion equation of a resistance temperature sensor, a temperature- > voltage conversion equation and a voltage- > temperature conversion equation and coefficient of a thermocouple, measurement conversion equations and coefficients of resistance temperature sensors of different types and various types of thermocouples such as S/R/B/N/K/E/J/T, and the like, the measurement conversion coefficient of the measurement conversion equation can be automatically selected only by configuring the type of the sensor, and the intelligent self-adaptive information processing from a measurement signal to temperature information is carried out on an access sensor, so that the flexibility, the adaptability and the efficiency are improved.

In an example, the measurement and control network device 15 may be a distributed network control device capable of implementing multi-node fast networking, for example, a device capable of implementing multi-node distributed fast networking and system integration based on a CAN bus may be used, and those skilled in the art may select the device as needed.

In one example, the network terminal assembly 16 may employ a corresponding type of port female socket, such as two LC1M-3.81 flange female sockets, RJ-11 terminals, RJ-45 terminals, etc., depending on the physical link, and the distributed intelligent instrumentation network cable may employ a multi-core cable.

In one example, the measurement and control network device 15, the network terminal assembly 16 and the distributed intelligent measurement and control network cable can be selected and collocated according to actual use scenarios. Illustratively, when the measurement and control network device 15 adopts an IPT12511 type information pipeline networking device, the network terminal assembly 16 may adopt two RJ-11 terminal female sockets, the power supply and measurement and control communication cable may adopt a four-core cable, two of the power supply and measurement and control communication cables may be used as communication lines of the IPT12511, the other two cables are respectively a power supply positive and a power supply negative, the bus type power supply of the node is realized, the power supply voltage is 9-36V, and the four-core cable is inserted into a double-end terminal interface of the information network interface through an RJ11 crystal head.

In one example, the bus power supply 17 can convert the bus power voltage introduced by the two terminals of the network terminal assembly 16 into a relatively stable low-voltage direct-current voltage, and to achieve high-efficiency conversion, a micro power module or other chips can be selected as needed, for example, a chip converting DC 9-36V into DC 3.3V or a chip converting DC 9-36V into DC 5V.

In one example, some processors integrate a plurality of functions of the constant current source 2, the multi-channel selection unit 8, the adjustable gain amplifier 10, the analog-to-digital converter 11, the voltage reference source 13, and the like, and technicians can also simplify the complexity of the node circuit design when designing the implementation according to the disclosed embodiment.

Referring to fig. 7, fig. 7 shows a schematic diagram of a temperature measuring system according to an embodiment of the disclosure.

In one possible embodiment, as shown in fig. 7, the thermometry system may include:

a plurality of the temperature sensor adaptive distributed intelligent measurement nodes 600;

the configuration device 700 is used for configuring the model of the connected temperature sensor for each temperature sensor self-adaptive distributed intelligent measurement node;

the power supply device 800 is used for supplying power to each temperature sensor self-adaptive distributed intelligent measurement node;

the temperature sensor adaptive distributed intelligent measurement nodes 600, the configuration device 700 and the power supply device 800 are connected in a networking manner through a network cable 18.

The temperature measurement system of the embodiment of the disclosure is characterized in that each temperature sensor self-adaptive distributed intelligent measurement node is connected with the configuration device through a network cable in a networking mode, so that the temperature measurement system of the distributed intelligent measurement and control network is constructed, automatic interaction and sharing of measurement and control information among nodes are realized, the types of the connected temperature sensors can be configured for each temperature sensor self-adaptive distributed intelligent measurement node by the configuration device, direct access and temperature self-adaptive measurement of various wire-system resistance-type temperature sensors and different types of thermocouples by each temperature sensor self-adaptive distributed intelligent measurement node are realized, management and expansion are facilitated, and the temperature measurement system has high flexibility, environmental adaptability and efficiency.

Illustratively, as shown in FIG. 7, each monitoring node in the system includes a network terminal assembly 16, the network terminal assembly 16 containing a T_pAnd T_nTwo identical interface terminals are connected with the distributed intelligent power supply device 800, the distributed online configuration device 700 and the N temperature sensor self-adaptive distributed intelligent measurement nodes 600 by cables 18, and a distributed intelligent measurement and control network can be automatically constructed. The nodes can be installed nearby the temperature sensor, the access of all the nodes has no sequential requirement, the mode of distributed deployment according to needs is very flexible and practical, and meanwhile, the problems of intelligent networking and power supply of the nodes are solved.

For example, as shown in fig. 7, an external control device may configure each temperature sensor adaptive distributed intelligent measurement node through a network (e.g., ethernet, WiFi, etc.) by using a configuration device, and as to an implementation manner thereof, the embodiment of the present disclosure is not limited.

It should be noted that the node front-end circuit of the temperature sensor adaptive distributed intelligent measurement node 600 shown in fig. 7 may include, for example, the interface function circuit, the wiring loop detection circuit, and the analog signal processing circuit described above, and for specific description, reference is made to the description of the node before, which is not repeated herein. The embodiment of the present disclosure does not limit the specific implementation manner of the power supply device and the configuration device, and those skilled in the art can implement the implementation by using the related technology as needed.

It should be noted that, the temperature sensor adaptive distributed intelligent measurement node may refer to the previous description, and is not described herein again.

The foregoing description of the embodiments of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. The utility model provides a temperature sensor self-adaptation distributed intelligence measurement node, a serial communication port, the node includes sensor coupling assembling, interface function circuit, wiring return circuit detection circuit, analog signal processing circuit, digital signal processing unit and communication unit, interface function circuit with sensor coupling assembling wiring return circuit detection circuit analog signal processing circuit reaches digital signal processing unit interconnect, digital signal processing unit with wiring return circuit detection circuit analog signal processing circuit communication unit interconnect, wherein:

the digital signal processing unit is used for communicating with an external communication link through the communication unit and controlling the interface function circuit, the wiring loop detection circuit and the analog signal processing circuit to execute the following actions:

actively detecting and automatically identifying the connection relationship between the temperature sensor and the sensor connecting assembly and the sensor parameters of the temperature sensor, wherein the connection relationship comprises the connection relationship between a lead of the temperature sensor and a connecting terminal in the terminal interface, and the connecting terminal is one or more of a plurality of terminals of the terminal interface;

2. The node of claim 1, wherein the actively detecting and automatically identifying the connection relationship of the temperature sensor to the sensor connection assembly and the sensor parameters of the temperature sensor comprises:

3. The node according to claim 1, wherein the interface function circuit comprises a multi-channel selection unit, a constant current source, a bias voltage source switching unit, a reference resistor, and a thermocouple cold junction compensation sensor, the analog signal processing circuit comprises an adjustable gain amplifier, an analog-to-digital converter, a voltage reference source switching unit, and a voltage reference source, and circuit parameters of the interface function circuit and one or more of the analog signal processing circuit and the wire loop detection circuit are automatically configured according to the connection relation and/or the sensor parameters, and the configuration comprises at least one of:

automatically configuring channel selection signals of the multi-channel selection unit to perform at least one of: establishing a connection relation between the constant current source and a current input terminal, establishing a connection relation between the connection terminal and an input end of the adjustable gain amplifier according to a preset pairing mode, and establishing a connection relation between the reference resistor and a reference terminal, wherein the current input terminal and the reference terminal are any two of the plurality of terminals;

automatically configuring a gain of the adjustable gain amplifier.

4. The node of claim 3, wherein the temperature sensor comprises a resistive temperature sensor comprising a two-wire resistive temperature sensor, a three-wire resistive temperature sensor, and a four-wire resistive temperature sensor, a thermocouple temperature sensor comprising S/R/B/N/K/E/J/T multiple types.

5. The node of claim 4, wherein if the temperature sensor is determined to be a two-wire resistance temperature sensor according to the connection relationship and/or the sensor parameter, and a first end of the temperature sensor is connected to the first connection terminal of the terminal interface and a second end of the temperature sensor is connected to the second connection terminal of the terminal interface according to the connection relationship, the signal processing unit is further configured to:

6. The node according to claim 4, wherein if the temperature sensor is determined to be a three-wire resistive temperature sensor according to the connection relationship and/or the sensor parameter, and a first end of the temperature sensor is connected to the first connection terminal of the terminal interface, a second end of the temperature sensor is connected to the second connection terminal of the terminal interface, and a third end of the temperature sensor is connected to the third connection terminal of the terminal interface, the signal processing unit is further configured to:

7. The node according to claim 4, wherein if it is determined that the temperature sensor is a four-wire resistive temperature sensor according to the connection relationship and/or the sensor parameter, and a first end of the temperature sensor is connected to the first connection terminal of the terminal interface, a second end of the temperature sensor is connected to the second connection terminal of the terminal interface, a third end of the temperature sensor is connected to the third connection terminal of the terminal interface, and a fourth end of the temperature sensor is connected to the fourth connection terminal of the terminal interface, the signal processing unit is further configured to:

8. The node according to claim 4, wherein if the temperature sensor is determined to be a thermocouple temperature sensor according to the connection relationship and/or the sensor parameter, and the first end of the temperature sensor is connected to the first connection terminal of the terminal interface and the second end of the temperature sensor is connected to the second connection terminal of the terminal interface according to the connection relationship, the signal processing unit is further configured to:

9. The node of claim 1,

the node further comprises: the bus power supply is used for supplying power to the nodes;

the communication unit includes:

10. The node of claim 1, wherein the interface function circuit comprises a multi-channel selection unit, a constant current source, a bias voltage source switching unit, a reference resistor, a thermocouple cold junction compensation sensor, and a temperature equalization chamber, the analog signal processing circuit comprises an adjustable gain amplifier, an analog-to-digital converter, a voltage reference source switching unit, and a voltage reference source, the communication unit comprises a measurement and control network device and a network terminal assembly, the node further comprises a bus power supply, the digital signal processing unit comprises a signal processor, each terminal interface comprises a first terminal, a second terminal, a third terminal, and a fourth terminal, the multi-channel selection unit comprises a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, and an eighth switch, and the wiring loop detection circuit comprises a first detection resistor, a second switch, a bias voltage source switching unit, a reference resistor, a thermocouple cold junction compensation sensor, and a temperature equalization chamber A second detection resistor, a first detection switch, a second detection switch, wherein,

the third terminal is connected to the first terminal of the fifth switch and the first terminal of the sixth switch,

11. A temperature measurement system, characterized in that, the temperature measurement system includes:

a plurality of temperature sensor adaptive distributed smart measurement nodes as claimed in any one of claims 1-10;