CN115379023A - HART communication device - Google Patents

Abstract

The invention discloses a HART communication device. The HART communication device includes a central processing unit and a plurality of communication units, each of which includes a protocol conversion module, a plurality of HART modulation and demodulation modules, a plurality of coupling modules and A plurality of signal conversion modules, the protocol conversion modules are respectively connected to the central processing unit and a plurality of the HART modulation and demodulation modules, each of the HART modulation and demodulation modules is connected to one of the coupling modules, and each of the coupling modules is connected to A signal conversion module, each of the signal conversion modules is connected to the central processing unit. The central processor of the device communicates with a plurality of external devices through the protocol conversion module, which can solve the shortage of the input interface and output interface of the central processor, and improve the communication efficiency.

Description

HART communication device

technical field

The present application relates to the field of HART communication, in particular to a HART communication device.

Background technique

The full name of the HART protocol is Highway Addressable Remote Transducer, which is a communication protocol between on-site intelligent instruments and control equipment launched by the American ROSEMOUNT company in 1985. However, the disadvantages of existing HART communication lie in relatively low communication bandwidth and long response time.

Contents of the invention

The technical problem to be solved by the present invention is to provide a HART communication device in order to overcome the defects of relatively low communication bandwidth and long response time of a single external device in the prior art.

The present invention solves the above technical problems through the following technical solutions:

A HART communication device, including a central processing unit and a plurality of communication units, each of which includes a protocol conversion module, a plurality of HART modulation and demodulation modules, a plurality of coupling modules and a plurality of signal conversion modules;

The protocol conversion module is respectively connected to the central processing unit and a plurality of HART modulation and demodulation modules;

Each of the HART modulation and demodulation modules is connected to one of the coupling modules, and each of the coupling modules is connected to a signal conversion module; each of the signal conversion modules is connected to the central processing unit;

The signal conversion module is used to convert the digital signal obtained from the central processing unit into an analog signal;

The protocol conversion module is used to sequentially output the communication data of the central processing unit to each HART modem module;

The HART modulation and demodulation module is used to obtain and modulate the signal output by the protocol conversion module;

The coupling module is used to superimpose the signal modulated by the HART modulation and demodulation module on the corresponding analog signal, and output it to an external device.

Preferably, the HART modulation and demodulation module is also used to sequentially acquire and demodulate the response signals of the external devices, and input the demodulated response signals to the protocol conversion module;

The protocol conversion module is also used to sequentially feed back each of the demodulated response signals to the central processing unit;

The signal conversion module is also used to sequentially convert the analog signal obtained from the external device into a digital signal and feed it back to the central processing unit.

Preferably, the central processing unit is connected to the plurality of protocol conversion modules through a data distribution module;

The data distribution module is used to sequentially distribute the communication data of the central processing unit to each of the protocol conversion modules.

Preferably, the data distribution module is also used to obtain response signals from the protocol conversion modules of the communication units, store the response signals, and feed them back to the central processing unit at regular intervals.

Preferably, the data distribution module is a Field Programmable Logic Gate Array.

Preferably, the central processing unit communicates with the data distribution module according to the PCIe protocol;

And/or, the data distribution module and the protocol conversion module communicate according to the SPI protocol;

And/or, the protocol conversion module communicates with the HART modem module according to the UART protocol.

Preferably, the signal conversion module is also connected to the external device through a filter module.

Preferably, the coupling module is also connected to the external device through a protection circuit, and the protection circuit is used to perform at least one of overvoltage protection, overcurrent protection and electrostatic protection on the external device.

Preferably, the HART communication device further includes an isolation module, the central processor is connected to the protocol conversion module through the isolation module, and the isolation module is used to electrically isolate the central processor from the protocol conversion module.

Preferably, the HART communication device further includes an isolation module, the central processor is also connected to the signal conversion module through the isolation module, and the isolation module is used to electrically isolate the central processor from the protocol conversion module.

The positive and progressive effect of the present invention is that: the central processor communicates with a plurality of external devices through the protocol conversion module, which can solve the shortage of the input interface and output interface of the central processor and improve the communication efficiency.

Since the communication channel between each external device and the central processing unit is independent, a single channel failure will not affect the communication of other external devices, which has good safety and reliability.

By adopting the architecture of the central processing unit, the data distribution module and the protocol conversion module, data is transmitted among the three through communication protocols of different rates, so that the communication efficiency is maximized.

Description of drawings

FIG. 1 is a schematic diagram of the first structure of the HART communication device in the first embodiment.

FIG. 2 is a second structural schematic diagram of the HART communication device in the first embodiment.

Detailed ways

The present invention is further illustrated below by means of examples, but the present invention is not limited to the scope of the examples.

Example 1

Referring to Fig. 1, the present embodiment provides a kind of HART communication device, comprises central processing unit 1 and a plurality of communication units, and each described communication unit all comprises protocol conversion module 2, a plurality of HART modem modules 3, a plurality of a coupling module 4 and a plurality of signal conversion modules 5;

The protocol conversion module 2 is connected to the central processing unit 1 and a plurality of HART modem modules 3 respectively;

Each of the HART modulation and demodulation modules 3 is correspondingly connected to one of the coupling modules 4, and each of the coupling modules 4 is connected to a signal conversion module 5; each of the signal conversion modules 5 is connected to the central processing unit 1;

The signal conversion module 5 is used to convert the digital signal obtained from the central processing unit 1 into an analog signal;

The protocol conversion module 2 is used to sequentially output the communication data of the central processing unit 1 to each HART modem module 3;

The HART modulation and demodulation module 3 is used to obtain and modulate the signal output by the protocol conversion module 2;

The coupling module 4 is used to superimpose the signal modulated by the HART modulation and demodulation module 3 on the corresponding analog signal, and output it to the external device 6 .

In this embodiment, the central processing unit 1 communicates with the protocol conversion module 2 according to the first communication protocol, and the protocol conversion module 2 communicates with each of the HART modem modules 3 according to the second communication protocol. The communication protocol communicates, and the rate of the first communication protocol is at least n times higher than the rate of the second communication protocol, wherein n is the number of HART modem modules 3 . In this embodiment, the protocol conversion module 2 can use a protocol conversion chip, and the protocol conversion chip can be four-way asynchronous transmission and reception, so that the communication of the first communication protocol that is faster in one way is converted into the second communication protocol in four ways for communication. communication.

Through this embodiment, in the present application, the communication data sent by the central processing unit 1 is sequentially input to each of the HART modulation and demodulation modules 3, and then the signal modulated by the HART modulation and demodulation module 3 is superimposed on the The corresponding analog signal is output to the external device 6 . This enables each external device 6 to receive signals sequentially, and the communication efficiency is greatly improved. Of course, in this embodiment, the rate of the second communication protocol only needs to meet the communication rate of the external device 6 . In this embodiment, the signal conversion module 5 may specifically be a digital-to-analog converter.

Moreover, in this embodiment, each external device 6 has a corresponding signal conversion module 5 , and when one signal conversion module 5 fails, the remaining signal conversion modules 5 will not be affected. In actual use, the channels from the protocol conversion module 2 to the coupling module 4 are also independent of each external device 6 .

In the above embodiment, the coupling module 4 can be a set of resistance-capacitance network, which couples the modulated signal to the analog current signal in the form of 1.2KHz and 2.2KHz sine waves (that is, the signal output by the signal conversion module 5 analog signal).

Specifically, the HART modulation and demodulation module 3 can also be used to sequentially acquire and demodulate the response signals of the external device 6, and input the demodulated response signals to the protocol conversion module 2;

The protocol conversion module 2 is also used to sequentially feed back each of the demodulated response signals to the central processing unit 1;

The signal conversion module 5 is also used to sequentially convert the analog signal obtained from the external device 6 into a digital signal and feed it back to the central processing unit 1 .

In this embodiment, the device can not only transmit the communication data of the central processing unit 1 to the external device 6, but also feed back the response signal of the external device 6 to the central processing unit 1 in turn to complete two-way communication. The HART modulation and demodulation module 3 is used for demodulating the response signal and digital signal sent by the external device 6 .

Referring to Fig. 2, specifically, the central processing unit 1 and a plurality of the protocol conversion modules 2 may also be connected through a data distribution module 7;

The data distribution module 7 is used to distribute the communication data of the central processing unit 1 to each of the protocol conversion modules 2 in sequence.

The data allocation module 7 in this embodiment is used to allocate corresponding data to different protocol conversion modules 2 . The central processing unit 1 and the data distribution module 7 may communicate through a third communication protocol, and the data distribution module 7 and the protocol conversion module 2 may communicate through a first communication protocol. The rate of the third communication protocol is at least m times higher than that of the first communication protocol, where m is the number of protocol conversion modules 2 connected to a single data distribution module 7 .

Specifically, the data distribution module 7 can also be used to obtain the response signals of the protocol conversion modules 2 of the communication units, store the response signals, and feed them back to the central processing unit 1 at regular intervals. In this embodiment, the central processing unit 1 does not need to receive the response signal every moment, but only needs to receive the stored response signal at a certain moment, which reduces the pressure on the central processing unit 1 .

Specifically, the data distribution module 7 may be a Field Programmable Gate Array (Field Programmable Gate Array, FPGA for short).

Specifically, the central processing unit 1 and the data distribution module 7 can communicate according to the PCIe protocol;

And/or, the data distribution module 7 and the protocol conversion module 2 can communicate according to the SPI protocol;

And/or, the protocol conversion module 2 and the HART modem module 3 can communicate according to the UART protocol.

Specifically, the signal converting module 5 can also be connected to the external device 6 through a filtering module 8 . In this embodiment, the filter module 8 is a low-pass filter module, which can filter the influence of the modulated communication signal and high-frequency noise on the analog signal.

Specifically, the coupling module 4 can also be connected to the external device 6 through a protection circuit 9, and the protection circuit 9 is used to perform at least one of overvoltage protection, overcurrent protection and electrostatic protection on the external device 6. .

Specifically, the central processing unit 1 is connected to the protocol conversion module 2 through an isolation module 10 , and the isolation module 10 is used to electrically isolate the central processing unit 1 from the protocol conversion module 2 .

Specifically, the central processing unit 1 is also connected to the signal conversion module 5 through an isolation module 10 , and the isolation module 10 is used to electrically isolate the central processing unit 1 from the protocol conversion module 2 .

In above-mentioned two embodiments, using isolation module 10 is that central processing unit 1 and protocol conversion module 2, central processing unit 1 and signal conversion module 5 are electrically isolated, when protocol conversion module 2 or signal conversion module 5 break down At this time, due to the setting of the isolation module 10, it avoids affecting the normal operation of the central processing unit 1.

In this embodiment, the central processing unit 1 can be divided into three stages: 1. Sending communication data; 2. Waiting for a response from the external device 6; 3. Receiving a response signal.

1. Sending communication data: After the central processing unit 1 is started, the central processing unit 1 can send communication data to the external device 6 in sequence, and after modulation by the HART modulation and demodulation module 3 and processing by the signal conversion module 5, the external device 6 will Processed communication data is received.

2. Waiting for the response from the external device 6: When the external device 6 receives the processed communication data, the external device 6 will respond after a certain period of time. While waiting for the external device 6 to respond, the central processing unit 1 can also respond to other external devices 6. The device 6 sends communication data, and the efficiency is greatly improved. In this stage, a preset time period can also be set. If the waiting time for the response data is within the preset time period, the central processing unit 1 will continue to wait for the response signal from the external device 6 .

3. Receive the response signal: when the external device 6 generates the corresponding response data, the central processing unit 1 will receive it. When all the response data of the external device 6 are received, the central processing unit 1 can once again respond to each external device 6 Send communication data. In this stage, if the waiting time exceeds the preset time period, it can be determined that the channel where the external device is located has a timeout error. If there is an error in the analysis of the received response data, it is determined that the response data is incorrect. When this stage ends, you can re-enter stage 1, and the cycle repeats.

In actual work, when the device of the present invention is started, it will be initialized. When the initialization is completed, the central processing unit 1 will send a signal, and the device will enter the state of sending communication data. When the device is initialized or the device is started, it is also possible to check whether the communication channel from the central processing unit 1 to each external device 6 is normal, and to feed back the abnormal situation to the central processing unit 1 .

When sending a communication signal, the content of the communication signal can be determined according to the actual situation. For example, the communication signal may include an inquiry command. The query command can be used to obtain the status of the external device or the information acquired by the external device.

Although the specific implementation of the present invention has been described above, those skilled in the art should understand that this is only an example, and the protection scope of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principle and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims (10)

1. A kind of HART communication device, is characterized in that, comprises central processing unit and a plurality of communication units, and each described communication unit all comprises protocol conversion module, a plurality of HART modem modules, a plurality of coupling modules and a plurality of signal conversion module; The protocol conversion module is respectively connected to the central processing unit and a plurality of HART modulation and demodulation modules; Each of the HART modulation and demodulation modules is connected to one of the coupling modules, and each of the coupling modules is connected to a signal conversion module; each of the signal conversion modules is connected to the central processing unit; The signal conversion module is used to convert the digital signal obtained from the central processing unit into an analog signal, and output it to an external device; The protocol conversion module is used to sequentially output the communication data of the central processing unit to each of the HART modem modules; The HART modulation and demodulation module is used to obtain and modulate the signal output by the protocol conversion module; The coupling module is used to superimpose the signal modulated by the HART modulation and demodulation module on the corresponding analog signal, and output it to an external device. 2. HART communication device as claimed in claim 1, is characterized in that, described HART modulation and demodulation module is also used for sequentially obtaining the response signal of described external equipment and demodulation, and the response signal after demodulation is input to The protocol conversion module; The protocol conversion module is also used to sequentially feed back each of the demodulated response signals to the central processing unit; The signal conversion module is also used to sequentially convert the analog signal obtained from the external device into a digital signal and feed it back to the central processing unit. 3. the HART communication device as claimed in claim 1, is characterized in that, also is connected by data distribution module between described central processing unit and a plurality of described protocol conversion modules; The data distribution module is used to sequentially distribute the communication data of the central processing unit to each of the protocol conversion modules. 4. HART communication device as claimed in claim 3, is characterized in that, described data distribution module is also used for obtaining the response signal of the protocol conversion module of each described communication unit, and each response signal is stored, and is regularly fed back to the central processing unit. 5. The HART communication device according to claim 3, wherein the data distribution module is a Field Programmable Logic Gate Array. 6. the HART communication device as claimed in claim 3, is characterized in that, communicates according to PCIe agreement between described central processing unit and described data distribution module; And/or, the data distribution module and the protocol conversion module communicate according to the SPI protocol; And/or, the protocol conversion module communicates with the HART modem module according to the UART protocol. 7. The HART communication device according to claim 1, wherein the signal converting module is further connected to the external device through a filtering module. 8. The HART communication device according to claim 1, wherein the coupling module is also connected to the external device through a protection circuit, and the protection circuit is used for overvoltage protection and overcurrent protection of the external device And at least one of electrostatic protection. 9. HART communication device as claimed in claim 1, is characterized in that, described HART communication device also comprises isolation module, and described central processing unit is connected described protocol conversion module by isolation module, and described isolation module is used for central The processor is electrically isolated from the protocol conversion module. 10. HART communication device as claimed in claim 1, is characterized in that, described HART communication device also comprises isolation module, and described central processing unit also connects described signal conversion module by isolation module, and described isolation module is used for The central processing unit is electrically isolated from the protocol conversion module.

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