CN2582057Y - Main circuit board based on field bus for temp/pressure sensor - Google Patents

Abstract

The main circuit board of the temperature/pressure sensor based on the field bus of the utility model is characterized in that it includes: a power conversion module, a microprocessor, a CAN interface module, a reset circuit module, a signal adjustment module, a first connector, and a second connector device. It converts the current signal output by the traditional temperature/pressure sensor into a digital signal, and transmits the processed digital signal to the field bus network through the CAN interface. In addition to the functions of sensor data acquisition and fieldbus communication, the circuit board also has the functions of self-diagnosing sensor faults, setting range, damping coefficient, engineering unit, and correcting sensor characteristics. It has the advantages of small installation size, complete functions, high reliability and fast data transmission speed.

Description

Main circuit board for fieldbus based temperature/pressure sensor

technical field

The utility model relates to a main circuit board of a temperature/pressure sensor based on a field bus.

Background technique

With the development of industrial production, more and more measurement and control points and parameters are needed. The traditional distributed control system has been difficult to meet the requirements, and a new open control system based on fieldbus has been replaced. A large number of smart devices or smart sensors are located in the on-site manufacturing and operating areas, and are at the forefront of the open control system. Therefore, their performance and reliability of output information are crucial to the entire system. An intelligent temperature/pressure sensor based on field bus will be paid more and more attention in the open control system.

Contents of the invention

The purpose of the utility model is to provide a main circuit board with a temperature/pressure sensor of a field bus (CAN). In addition to the functions of sensor data acquisition and fieldbus communication, the circuit board also has the functions of self-diagnosing sensor faults, setting range, damping coefficient, engineering unit, and correcting sensor characteristics. It has the advantages of small installation size, complete functions, high reliability and fast data transmission speed.

The technical measures taken by the utility model are: the main circuit board of the temperature/pressure sensor based on the field bus, which is characterized in that it includes: a power conversion module, a microprocessor, a CAN interface module, a reset circuit module, a signal adjustment module, a first connector, second connector; where:

The power conversion module is used to change the input 24V power supply voltage into a 5V working voltage, and provide a set of stable working voltages for each module of the main circuit board;

The microprocessor is used for collecting sensor signals, data processing and calculation, and outputting processing results, and its input terminals are respectively connected to the output terminals of the signal adjustment module and the reset circuit module;

CAN interface module, which is used to provide differential transmission function to CAN bus, and differential reception to CAN bus, and automatically complete all functions of physical layer and data link layer according to the standard, and it is bidirectionally connected with the microprocessor .

The reset circuit module is used to generate a level signal that changes from high to low and from low to high, and performs an initial power-on reset on the microprocessor and the CAN interface module respectively, and its output terminals are respectively connected to the microprocessor. The processor is connected with the CAN interface module.

The signal adjustment module is used to transform the input sensor current signal into a voltage signal, and perform signal zero point adjustment and filtering. Its output is connected with the microprocessor.

The first connector is used to connect the working power supply and the sensor signal and to connect to the external field bus, and it is bidirectionally connected to the field bus interface module, and its output end is connected to the power conversion module and the signal adjustment module;

The second connector is used for programming and debugging the microprocessor, and is bidirectionally connected with the microprocessor.

The main circuit board of the temperature/pressure sensor based on the above-mentioned field bus, wherein, the main circuit board also includes a special connection to the ground wire, and the special connection is: first connect the work of all the microprocessors on the main circuit board The ground wire of the power supply and the ground wire of the power supply used for the analog/digital conversion interface are connected separately, and then the two ground wires are connected with a wire.

Because the utility model adopts the above technical scheme, it converts the current signal output by the traditional temperature/pressure sensor into a digital signal, and transmits the processed digital signal to the field bus network through the CAN interface, thus having high precision and High stability, and has the characteristics of low price-performance ratio.

Description of drawings

Concrete structure of the present utility model is further provided by following embodiment and accompanying drawing thereof.

Fig. 1 is the functional block diagram of the utility model main circuit board.

Fig. 2 is a circuit diagram of an embodiment of the main circuit board of the present invention.

Detailed ways

Please refer to Figure 1 and Figure 2. The main circuit board of a temperature/pressure sensor with a field bus provided by the utility model selects a patch-type single-chip microprocessor of the model ADUC812, and forms a single-chip microcomputer system through a CAN controller interface circuit. It includes: a power conversion module 1, a microprocessor 2, a field bus (CAN) interface module 3, a reset circuit module 4, a signal adjustment module 5, a first connector 6, and a second connector 7; wherein:

The power conversion module 1 is used to change the input 24V power supply voltage into a 5V working voltage, and provides a group of stable working voltages for each module of the main circuit board of the present utility model. It consists of a three-terminal voltage regulator tube and two Consists of only monolithic capacitors.

The microprocessor 2 is used for collecting sensor signals, data processing and calculation, and outputting processing results. It consists of a single-chip microprocessor model ADUC812, a crystal oscillator, a resistor and 7 capacitors. It is connected with the power conversion module 1 mentioned above. ADUC812 is a fully integrated 12-bit data acquisition system, which contains 8K bytes of on-chip flash/electrically erasable program memory and 256 bytes of on-chip data memory. It converts the collected sensor signals into digital signals, and after data processing, calculation and self-diagnosis, it sends data to the upper computer according to the communication format of CAN field bus. In order to improve the accuracy of the A/D data collection of the utility model, the utility model has carried out special processing connection to the ground wire in actual use, that is: earlier connect the working power supply ground wires of all microprocessors on the main circuit board Connect to the ground wire of the power supply for analog/digital conversion separately, and then use a wire to connect the two ground wires. After processing in this way, the accuracy of the collected data of the utility model can be greatly improved.

CAN interface module 3 is used to provide differential transmission function to CAN bus and differential reception to CAN bus, and automatically complete all functions of physical layer and data link layer according to the standard. It consists of a SJA1000 CAN controller 1. A CAN controller interface whose model is 82C250, a crystal oscillator and several resistors and capacitors are composed, and it is bidirectionally connected with the microprocessor 2.

The reset circuit module 4 is used to generate a level signal that changes from high to low and from low to high, respectively to the ADUC812 single-chip microprocessor on the microprocessor 2 and the CAN interface module 3 The SJA1000CAN controller of SJA1000CAN performs the initial power-on reset. It is composed of a SMD monostable integrated circuit model 74LS123 and several resistors and capacitors. Its output terminal is connected with the microprocessor 2 and the CAN interface module 3 .

The signal adjustment module 5 is used to transform the input sensor current signal into a voltage signal, and perform signal zero point adjustment and filtering. It is made up of a zero adjustment potentiometer and several resistances, electric capacity, and it is connected with described microprocessor 2.

The first connector 6 is used to connect the working power supply and the sensor signal and to connect to the external field bus. It is bidirectionally connected to the field bus interface module, and its output end is connected to the power conversion module 1 and the signal adjustment module 5. ;

The second connector 7 is used for programming and debugging the microprocessor 2, and it is bidirectionally connected with the microprocessor 2; the output of the second connector 7 is connected with an external computer.

Due to the adoption of the scheme, that is, the use of fully integrated 12-bit data acquisition system components, the printed circuit board of the utility model is small in size, complete in function, high in precision and stability, and has the characteristics of low price-performance ratio.

The working principle of the utility model is: the analog/digital conversion interface in the microprocessor converts the electrical signal output by the sensor into a digital signal through data acquisition, performs logic processing and calculation in the microprocessor, and sends the calculation result to the CAN interface Carry out data communication, and then transmit the processed digital signal to the field bus network through the CAN interface.

The main circuit board of the temperature/pressure sensor with field bus of the utility model not only has the functions of sensor data acquisition and field bus communication, but also has the functions of self-diagnosing the sensor's fault, setting the range and damping coefficient, correcting the characteristics of the sensor and so on. It can make the utility model more adaptable to the increasingly complicated needs of the current modern industrialized mass production.

Claims (2)

1. The main circuit board of the temperature/pressure sensor based on the field bus is characterized in that it includes: a power conversion module, a microprocessor, a field bus interface module, a reset circuit module, a signal adjustment module, a first connector, and a second connection device; where: The power conversion module is used to change the input 24V power supply voltage into a 5V working voltage, and provide a set of stable working voltages for each module of the main circuit board; The microprocessor is used for collecting sensor signals, data processing and calculation, and outputting processing results, and its input terminals are respectively connected to the output terminals of the signal adjustment module and the reset circuit module; The field bus interface module is used to provide differential sending function to the field bus, and differential reception to the field bus, and automatically complete all functions of the physical layer and data link layer according to the standard, it is compatible with the micro-processing connected bidirectionally. The reset circuit module is used to generate a level signal that changes from high to low and from low to high, and performs an initial power-on reset on the microprocessor and the field bus interface module respectively, and its output terminals are respectively connected to The microprocessor is connected with the field bus interface module. The signal adjustment module is used to transform the input sensor current signal into a voltage signal, and perform signal zero point adjustment and filtering. Its output is connected with the microprocessor. The first connector is used to connect the working power supply and the sensor signal and connect to the external field bus, it is bidirectionally connected to the field bus interface module, and its output end is connected to the power conversion module and the signal adjustment module, The second connector is used for programming and debugging the microprocessor, and is bidirectionally connected with the microprocessor. 2. The main circuit board of the temperature/pressure sensor based on field bus according to claim 1, characterized in that, said main circuit board also includes a special connection to the ground wire, and the special connection is: first connect the main circuit The working power ground wires of all microprocessors on the board and the ground wires of the power supply for analog/digital conversion are respectively connected, and then the two ground wires are connected with wires.

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