Field bus equipment testing device

Abstract

The invention belongs to the technical field of oilfield field bus digital communication and equipment management, and particularly relates to a field bus equipment testing device. According to the field bus equipment testing device provided by the invention, testing and diagnosis of Profibus equipment, ModBus communication equipment and equipment with an HART (Highway Addressable Remote Transducer) bus function can be realized by the field bus equipment testing device, and rapid testing of the field bus equipment for communication based on different types of field buses can be realized. The invention relates to a field bus equipment testing device, which comprises a field bus equipment testing device box body, wherein a CPU module, an intelligent control module and a DP communication module are installed in the housing; a Siemens S7-300 processing unit is selected as the CPU module; the intelligent control module adopts a Siemens FM357-2 motion control processing unit; and a Siemens CP342-5PROFIBUS communication processing unit is selected as the DP communication module.

Description

Technical Field

[0001] The invention belongs to the technical field of oil field field bus digital communication and equipment management, and in particular relates to a field bus equipment testing device. Background Art

[0002] The oilfield fieldbus equipment test device replaces the traditional hard-wired signal transmission with digital communication, realizing two-way, digital connection communication of various intelligent devices and automatic control systems on the oilfield site. Therefore, it has been widely used in the technical fields of petrochemical, oil and gas, oil storage and transportation, thermal power, etc. However, the inventor found in the further research process that the existing oilfield fieldbus equipment test device has many defects in specific applications, such as unstable communication (signal) and abnormal communication failure, due to the different types of buses relied on by the oilfield fieldbus equipment test device and the different communication technologies used by various buses.

[0003] Specifically, the types of oilfield fieldbus can be divided into the following categories: PROFIBUS bus; PROFIBUS bus is a component of the PROFIBUS bus protocol jointly launched by 13 companies led by SIEMENS and scientific research institutions in 1987. Once launched, the bus has been widely used in various industries due to its many excellent features, and has become the German national industrial standard, the European standard in 1996, and the Chinese machinery industry standard in 2001. PROFIBUS is mainly suitable for high-speed signal transmission between distributed devices, especially to ensure high-speed data exchange between devices such as sensors and actuators and controllers in the bus network.

[0004] RS485 bus; In the field of automation, with the development of distributed control systems, there is an urgent need for a bus that is suitable for long-distance digital communication. Based on the RS-422 standard, EIA has developed an RS-485 bus standard that supports multiple nodes, long distances and high reception sensitivity. The RS485 bus is a standard that defines the electrical characteristics of drivers and receivers in balanced digital multi-point systems. The standard is defined by the Telecommunications Industry Association and the Electronics Industry Alliance. The RS-485 bus uses half-duplex operation and supports multi-point data communication. The RS-485 bus network topology generally adopts a terminal-matched bus structure. That is, a bus is used to connect each node in series, and a ring or star network is not supported. RS-485 uses balanced transmission and differential reception to achieve communication: the transmitter converts the TTL level signal of the serial port into two differential signal a and b outputs, and after cable transmission, the differential signal is restored to a TTL level signal at the receiving end. Since the transmission line usually uses twisted pair and differential transmission, it has a strong ability to resist common-mode interference. The bus transceiver is very sensitive and can detect voltages as low as 200mv. Therefore, the transmission signal can be restored at a distance of one kilometer. The maximum communication distance of RS-485 is about 1219m, and the maximum transmission rate is 10mb / s. The transmission rate is inversely proportional to the transmission distance. At a transmission rate of 10kb / s, the maximum communication distance can be reached. If a longer distance is required, a 485 repeater is required. RS-485 adopts half-duplex working mode and supports multi-point data communication. The RS-485 bus network topology generally adopts a terminal matching bus structure. That is, a bus is used to connect each node in series, and a ring or star network is not supported. If a star structure is required, a 485 repeater or a 485 hub must be used. The RS-485 bus generally supports a maximum of 32 nodes. If a special 485 chip is used, it can reach 128 or 256 nodes, and the maximum can support up to 400 nodes. The MODBUS RTU protocol based on the RS-485 bus is widely used in various automation equipment and instruments. Modbus is a serial communication protocol that was published by Modicon (now Schneider Electric) in 1979 for communication with programmable logic controllers (PLCs). Modbus has become the industry standard for communication protocols in the industrial field (De facto), and is now a common connection method between industrial electronic equipment. It is widely used in industry due to its many advantages, such as being publicly published and without copyright requirements, easy to deploy and maintain, and having no restrictions on vendors modifying local bits or bytes. However, there is currently a lack of effective RS-485 bus detection technology and equipment.

[0005] HART bus; HART bus was first launched by Rosemount, and then nearly 80 instrument manufacturers or companies joined the HART bus camp. In order to better promote the HART bus protocol, the HART Communication Foundation was established in 1993. HART bus is an open communication protocol. The physical layer uses FSK technology, that is, a frequency signal is superimposed on the 4-20mA analog signal, and the digital signal quantity is distinguished by changing the frequency of the frequency signal. In the data link layer, all communication information formats are clarified through the HART communication protocol. Because it can realize the function of digital signal transmission without changing the original analog signal transmission line, the HART bus has strong market competitiveness and has been well developed and promoted.

[0006] In order to adapt to the above-mentioned different types of buses, technicians have made many technical attempts, for example: Application number: CN201810623693.8, name: A patent document of a microgrid control and detection platform records the following technical scheme. Specifically, the platform includes a signal module, a loading module and a control module; the signal module is used to output a first simulation signal to the control module; the loading module is used to output a second simulation signal to the control module; the control module is used to receive the first simulation signal of the signal module and the second simulation signal of the loading module, and convert the first simulation signal and the second simulation signal into their respective corresponding simulation digital signals and output them to the power management system for identification, and is used to receive the control output signal transmitted by the power management system, convert the control output signal into their respective corresponding feedback signals and transmit them to the signal module and the loading module for display. The microgrid control and detection platform provided by the present invention can simulate the working conditions and state changes of the power management system equipment, and provide an effective testing and verification method for the control strategy of the complex power management system.

[0007] However, the prior art including the above patent documents still cannot effectively solve the defects of the above communication (signal) instability and abnormal communication failure. Therefore, it is urgent for technical personnel in this field to provide a new field bus equipment testing device to realize the detection, analysis and judgment of the communication signals of different types of field buses and their equipment. Summary of the invention

[0008] The invention provides a fieldbus equipment testing device, which can realize the testing and diagnosis of Profibus bus equipment, ModBus communication equipment and equipment with HART bus function, and can realize the rapid testing of fieldbus equipment communicating based on different types of fieldbuses.

[0009] In order to solve the above technical problems, the present invention adopts the following technical solutions: A fieldbus device testing device comprises: a fieldbus device testing device box; a CPU module, an intelligent control module, and a DP communication module are installed in the fieldbus device testing device box; The CPU module uses a processing unit of Siemens S7-300; the intelligent control module uses a motion control processing unit of Siemens FM357-2; and the DP communication module uses a PROFIBUS communication processing unit of Siemens CP342-5.

[0010] Preferably, the fieldbus device test device box is further equipped with: a power module; the power module is used to convert the input 220V AC voltage into the output 12V, 24V DC voltage, so as to power other modules in the fieldbus device test device.

[0011] More preferably, the method further comprises: a bandpass filter circuit arranged on the path between the box of the field bus equipment test device and the bus to be tested; the bandpass filter circuit is composed of two dual operational amplifiers with chip model NE5532.

[0012] More preferably, it also includes: an amplifying circuit arranged on the path between the box of the field bus equipment testing device and the bus to be tested; the amplifying circuit is composed of a dual operational amplifier with a chip model of NE5532; wherein the VCC pin of the dual operational amplifier with a chip model of NE5532 is connected to a DC voltage of +12V, and the GND pin of the dual operational amplifier with a chip model of NE5532 is grounded.

[0013] More preferably, the method further includes: a photoelectric coupling circuit is provided on the path between the box of the field bus equipment testing device and the bus to be tested; the photoelectric coupling circuit is composed of a linear photocoupler unit with a chip model of PC817.

[0014] Preferably, the method further comprises: a DP bus terminal controller connected to the DP bus in the bus to be tested; the DP bus terminal controller is used to control the turning on and off of the terminal resistance circuit adapted to the DP bus and the DP bus data circuit.

[0015] Preferably, a RS485 communication module is also installed in the box of the field bus equipment testing device; wherein the RS485 communication module uses a communication processing unit of model Siemens CP341.

[0016] More preferably, it also includes: a signal isolation repeater connected to the RS485 communication module for communication; the signal isolation repeater is provided with a photoelectric isolation unit.

[0017] The present invention provides a fieldbus device test device, which includes a fieldbus device test device box; wherein the fieldbus device test device box is further installed with a CPU module, an intelligent control module, a DP communication module, and an RS485 communication module. The fieldbus device test device with the above structural features has at least the following technical advantages compared to the prior art: 1. It can realize real-time detection and performance testing of PROFIBUS bus devices; 2. It can realize real-time detection and performance testing of ModBus communication equipment; 3. Real-time detection and performance testing of HART bus intelligent devices can be realized; 4. It has strong adaptability to various mainstream buses and can realize fast on-site communication with a variety of bus devices, filling the gap in on-site testing of bus devices in the existing technology; 5. Cooperating with the host computer, it can realize real-time and periodic measurement of bus equipment, and the test results are more reliable. It is easy to use with one-key operation and has the extended function of automatic report production. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0019] Figure 1 A structural schematic diagram of a field bus equipment testing device provided by the present invention; Figure 2 is a circuit diagram of a bandpass filter circuit; Figure 3 is a circuit diagram of an amplifier circuit; Figure 4 is a circuit diagram of a photoelectric coupling circuit; Figure 5 This is a schematic diagram of the architecture of the DP bus terminal controller. DETAILED DESCRIPTION

[0020] The invention provides a fieldbus equipment testing device, which can realize the testing and diagnosis of Profibus bus equipment, ModBus communication equipment and equipment with HART bus function, and can realize the rapid testing of fieldbus equipment communicating based on different types of fieldbuses. Embodiment 1

[0021] The present invention provides a fieldbus equipment testing device, such as Figure 1As shown, it specifically includes: a fieldbus device test device box. Among them, the fieldbus device test device box further has a CPU module, an intelligent control module, and a DP communication module installed therein.

[0022] As a preferred embodiment of the present invention, the CPU module preferably uses a Siemens S7-300 processing unit. The Siemens S7-300 processing unit is a programmable logic control series product produced by Siemens, Germany, and has many characteristics such as short cycle, high processing speed, powerful instruction set, compact product design, etc.

[0023] The intelligent control module preferably uses the Siemens FM357-2 motion control processing unit. The Siemens FM357-2 motion control processing unit is an intelligent motion control product produced by Siemens, Germany, which can realize path and positioning control of up to 4 axes and can be widely used in many fields from independent single-axis positioning to multi-axis interpolation continuous path control.

[0024] The DP communication module preferably uses the Siemens CP342-5 PROFIBUS communication processing unit. The Siemens CP342-5 PROFIBUS communication processing unit is connected to the PROFIBUS bus through the configured integrated PROFIBUS DP interface, so it can be used to build a PROFIBUS master station and a PROFIBUS slave station.

[0025] In addition, as a more preferred embodiment of the present invention, an RS485 communication module is preferably installed in the box of the field bus equipment test device. Among them, the RS485 communication module preferably uses a communication processing unit of Siemens CP341. The communication processing unit of Siemens CP341 is a communication processing product produced by Siemens, Germany, which specifically interfaces with a third-party system through a simple transmission protocol to realize user program calling and control of the third-party system.

[0026] Further preferably, the RS485 communication module is also connected to a signal isolation repeater, which is equipped with a photoelectric isolation unit, specifically used to receive and amplify RS485 communication signals, so as to extend the bus (signal transmission) distance and increase the number of network terminals, and its built-in photoelectric isolation unit is used to improve the stability and reliability of the communication system. Embodiment 2

[0027] Embodiment 2 includes all the technical features of embodiment 1. In addition, embodiment 2 further discloses and defines a power module.

[0028] Specifically, the power supply module is used to supply power to other modules in the field bus equipment testing device, and its working mode is to convert the input 220V AC voltage into the output 12V, 24V DC voltage. Embodiment 3

[0029] Embodiment 3 includes all the technical features of embodiment 1. In addition, embodiment 3 further discloses and defines a bandpass filter circuit.

[0030] It is worth noting that the bandpass filter circuit is arranged on the path between the fieldbus equipment test device box and the bus to be tested, as shown in Figure 2 As shown, it is composed of two dual operational amplifiers with chip model NE5532. The bandpass filter circuit is used to filter out periodic interference signals to ensure communication quality. Compared with the standard operational amplifier filter circuit in the prior art, the bandpass filter circuit of the above structure has better noise performance, excellent output drive capability, relatively high small signal bandwidth, and adaptability to a wider power supply voltage range. Embodiment 4

[0031] The fourth embodiment includes all the technical features of the first embodiment. In addition, the fourth embodiment further discloses and defines an amplifying circuit.

[0032] Specifically, the amplifier circuit is arranged in the path between the field bus equipment test device box and the bus to be tested, such as Figure 3 As shown, the amplifier circuit is composed of a dual operational amplifier with a chip model of NE5532; wherein the VCC pin of the dual operational amplifier with a chip model of NE5532 is connected to a +12V DC voltage, and the GND pin of the dual operational amplifier with a chip model of NE5532 is grounded. The amplifier circuit with the above structure is particularly suitable for use with a single power supply with a wide signal voltage range, thereby further amplifying the bus (transmission) signal and ensuring stable communication of signal data. Embodiment 5

[0033] The fifth embodiment includes all the technical features of the first embodiment. In addition, the fifth embodiment further discloses and defines a photoelectric coupling circuit.

[0034] Specifically, the photoelectric coupling circuit is arranged on the path between the field bus equipment test device box and the bus to be tested, such as Figure 4 As shown, it is specifically composed of a linear optocoupler unit with a chip model of PC817. The linear optocoupler unit with a chip model of PC817 belongs to a linear optocoupler and can be used to achieve the effect of isolating the upper and lower level circuits so that the upper and lower level circuits do not interfere with each other. Embodiment 6

[0035] The sixth embodiment includes all the technical features of the first embodiment. In addition, the sixth embodiment further discloses and defines a DP bus terminal controller.

[0036] like Figure 5 As shown, the DP bus terminal controller is connected to the DP bus in the bus to be tested, and the DP bus terminal controller controls the terminal resistance circuit and the DP bus data circuit adapted to the DP bus respectively.

[0037] When the switch of the DP bus terminal controller is turned to "ON", the terminal resistance circuit and the DP bus data circuit adapted to the DP bus are both turned on, and the field bus equipment testing device provided by the present invention is connected to the DP bus in the bus to be tested. When the switch of the DP bus terminal controller is turned to "OFF", the terminal resistance circuit and the DP bus data circuit adapted to the DP bus are both disconnected; at this time, the devices on the serial network can be adjusted to match (appropriate) terminal resistance, thereby solving the problems of impedance discontinuity and impedance mismatch, and avoiding signal reflection interference and idle network data confusion.

[0038] The present invention provides a fieldbus device test device, which includes a fieldbus device test device box; wherein the fieldbus device test device box is further installed with a CPU module, an intelligent control module, a DP communication module, and an RS485 communication module. The fieldbus device test device with the above structural features has at least the following technical advantages compared to the prior art: 1. It can realize real-time detection and performance testing of PROFIBUS bus devices; 2. It can realize real-time detection and performance testing of ModBus communication equipment; 3. Real-time detection and performance testing of HART bus intelligent devices can be realized; 4. It has strong adaptability to various mainstream buses and can realize fast on-site communication with a variety of bus devices, filling the gap in on-site testing of bus devices in the existing technology; 5. Cooperating with the host computer, it can realize real-time and periodic measurement of bus equipment, and the test results are more reliable. It is easy to use with one-key operation and has the extended function of automatic report production.

[0039] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A fieldbus equipment testing device, characterized in that: The invention comprises: a fieldbus equipment test device box; a CPU module, an intelligent control module and a DP communication module are installed in the fieldbus equipment test device box; The CPU module uses a processing unit of Siemens S7-300; the intelligent control module uses a motion control processing unit of Siemens FM357-2; and the DP communication module uses a PROFIBUS communication processing unit of Siemens CP342-5.

2. A fieldbus device testing device according to claim 1, characterized in that: The fieldbus device test device box also has a power module installed therein; the power module is used to convert the input 220V AC voltage into the output 12V, 24V DC voltage, thereby supplying power to other modules in the fieldbus device test device.

3. A fieldbus equipment testing device according to claim 1, characterized in that: It also includes: a bandpass filter circuit arranged on the path between the box of the field bus equipment test device and the bus to be tested; the bandpass filter circuit is composed of two dual operational amplifiers with chip model NE5532.

4. A fieldbus equipment testing device according to claim 1, characterized in that: It also includes: an amplifying circuit arranged on the path between the box of the field bus equipment testing device and the bus to be tested; the amplifying circuit is composed of a dual operational amplifier with a chip model of NE5532; wherein the VCC pin of the dual operational amplifier with a chip model of NE5532 is connected to a +12V DC voltage, and the GND pin of the dual operational amplifier with a chip model of NE5532 is grounded.

5. A fieldbus equipment testing device according to claim 1, characterized in that: It also includes: a photoelectric coupling circuit is arranged on the path between the box of the field bus equipment test device and the bus to be tested; the photoelectric coupling circuit is composed of a linear photocoupler unit with a chip model of PC817.

6. A fieldbus equipment testing device according to claim 1, characterized in that: It also includes: a DP bus terminal controller connected to the DP bus in the bus to be tested; the DP bus terminal controller is used to control the closing and opening of the terminal resistance circuit adapted to the DP bus and the DP bus data circuit.

7. A fieldbus equipment testing device according to claim 1, characterized in that: The box of the field bus equipment testing device is also equipped with an RS485 communication module; wherein the RS485 communication module uses a communication processing unit of Siemens CP341.

8. A fieldbus equipment testing device according to claim 7, characterized in that: It also includes: a signal isolation repeater connected to the RS485 communication module; the signal isolation repeater is equipped with a photoelectric isolation unit.

Images