Three-way HART (highway addressable remote transducer) extraction switching module
By designing a three-way HART acquisition adapter module, using impedance matching resistors and direct-blocking capacitors, the impedance matching and common mode interference problems of HART signal acquisition in the bottom plate safety gate are solved, and the fast, safe acquisition and transformation cycle of HART signals are achieved.
Patent Information
- Application Number
- CN202422123629.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-30
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-08-30
AI Technical Summary
The prior art is difficult to securely separate and acquire HART signals in bottom plate safety gates, especially in terms of impedance matching and common mode interference.
A three-way HART extraction and adapter module is designed. This module uses impedance matching resistors and direct-blocking capacitors to achieve the safe extraction of HART signals and the common ground solution of signal.
It realizes fast and secure collection of HART signals, reduces transformation cycle and cost, is suitable for most existing safety grid bottom plates, and supports the use of third-party hardware and software.
Smart Images
Figure CN223039350U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of safety barrier signal acquisition, and particularly relates to a three-way HART extraction transfer module. Background Technique
[0002] With the progress of technology, intelligent instruments have become the mainstream of field instruments, and it is a basic industry requirement for intelligent instruments to support HART. In the early stage, due to circuit design and software and hardware function limitations of control systems, non-intelligent instruments (such as electric type III) accounted for a large proportion in field instruments and did not have HART function itself.
[0003] Since the HART patent is held by Emerson, other brands need to pay a large amount of patent licensing fees to use this technology, resulting in a high cost of HART-supporting cards. Unless specifically required by users, DCS manufacturers generally do not use HART-supporting cards for system integration. Among them, Siemens, Yokogawa, Honeywell, Zhongkong ECS700, and Hollysys prefer non-HART models during system selection.
[0004] In addition, some instrument manufacturers have a relatively simple hart function in instrument design due to lack of in-depth digestion of the HART protocol, and the utilization value of data transmission is not high. Moreover, in the early years, factories did not have equipment management system requirements, and there were no strict requirements for HART signal acquisition and management in engineering construction. Users did not have a deep understanding of HART and could not experience its benefits, so the terminal demand desire was not strong.
[0005] In recent years, the country has paid more and more attention to equipment upgrading and transformation, and the process industry has continuously put forward requirements for the acquisition and monitoring of intelligent instrument information. The original system is still working normally, and it requires more investment and shutdown time for transformation to start over. Replacing with HART-supporting cards from DCS manufacturers is also too costly, and the acquisition speed is restricted, which is difficult for users to accept. Using third-party HART acquisition equipment to safely extract HART signals is a new requirement and problem put forward by the process control industry.
[0006] Large-scale process systems are widely used in petrochemical, refining, chemical and other fields, mainly in flammable and explosive occasions. A large number of safety barriers are used to form an intrinsically safe explosion-proof system, and a considerable part of them are bottom plate type safety barriers. Due to the lack of HART requirements in the early stage, the bottom plates designed in the early years generally do not have HART signal output channels, and the on-site instruments and safety barriers in use all support HART. The key problem is how to safely separate the HART signal.
[0007] Two problems need to be solved for HART signal separation: one is impedance matching, and the other is to block direct current to reduce common-mode interference and ensure signal safety.
[0008] The input and output impedances of the AI / AO cards designed by each DCS manufacturer are different. Due to the need to expand the load capacity, the current card designs try to minimize the impedance as much as possible, and most of them cannot meet the lower limit requirement that the HART signal impedance is not less than 250 ohms.
[0009] In this case, there are the following technical routes for HART acquisition transformation:
[0010] (1) Directly replace the DCS cards of the same brand with HART functions and use the device management software of the DCS manufacturer;
[0011] (2) Directly replace the DCS cards of the same brand with HART functions and use the professional device management software of a third party;
[0012] If the DCS cards of the same brand with HART functions are replaced, there are the following disadvantages:
[0013] a) High equipment investment: All the analog cards of the DCS system that need to be upgraded are involved, and their costs account for a relatively large proportion in the whole system. Especially for transformation projects, the selection of equipment is exclusive, and the price is negotiated one-on-one with intelligence, and it is impossible to conduct bidding and price comparison, resulting in the cost of replacing the cards being close to the hardware investment of the original whole system;
[0014] b) Limited software selection: DCS brands focus on process control data processing and do not have an advantage in factory device management software. On the contrary, most companies specializing in factory management software in the industry have been in business for many years, have a wide range of contacts, and thus have rich experience and can provide users with more experience sets. Only using the hardware channels of DCS brands, DCS manufacturers are not very enthusiastic about cooperating with third-party software. The software and hardware belong to different contractors, and it is easy to have disputes in project construction and later maintenance. Experienced users will try to avoid this mode;
[0015] c) Slow acquisition speed: Since the cards undertake both the functions of process data acquisition and HART data acquisition, in order to ensure the response speed of process data, the HART acquisition speed is generally sacrificed. As a result, in actual applications, it takes several hours to poll a system of thousands of instruments once, which greatly affects the user experience.
[0016] (3) Adopt a third-party HART acquisition device for independent HART data management and cooperate with the device management software of a third party; This is the optimal solution recognized by the instrument technology community.
[0017] This solution involves replacing the backplane with a HART interface, and the following problems exist:
[0018] a) Designing a new backplane requires the cooperation of the original backplane manufacturer. However, the original manufacturers MTL and P+F are international first-tier brands with a wide variety of products and a long development cycle for new products. If a single product does not have sufficient order volume and market space, the manufacturer generally will not respond to such a demand.
[0019] b) Replacing the backplane will discard the original backplane, resulting in a huge waste of equipment materials.
[0020] c) Replacing the backplane requires removing all safety barriers and signal cables. After restoration, the system needs to be re-tested and jointly adjusted, which requires a large amount of labor, a long transformation cycle, and brings certain risks.
[0021] Therefore, how to design a simple modular product and solve the problem of fast signal separation is an urgent problem to be solved in the current industry. Summary of the Invention
[0022] The utility model aims to make up for the deficiencies of the prior art and provides a tee-type HART extraction and transfer module that can be directly connected in series between the existing safety barrier backplane and the system prefabricated cable, is conveniently plugged into the existing backplane product, allows the original signal to be transferred and pass through normally, and safely extracts the HART signal.
[0023] The utility model is realized by the following technical solutions:
[0024] A tee-type HART extraction and transfer module includes a transfer module arranged on the safety barrier backplane. The safety barrier backplane is provided with a backplane D-SUB male socket. The bottom of the transfer module is provided with a D-SUB female socket, and the D-SUB female socket is plugged into the backplane D-SUB male socket. Above the transfer module, there are a D-SUB male socket and a pin header. The D-SUB female head of the system cable is plugged into the D-SUB male socket, and the end of the system cable is connected to the DCS card. The transfer module contains several signals, and each signal uses two pins. One end of the signal positive terminal is connected to the D-SUB male socket through an impedance matching resistor, and the other end is connected to the corresponding pin of the pin header. The signal negative terminal is directly introduced into the D-SUB male socket from the D-SUB female socket and is also connected to the pin header through a blocking capacitor. The transfer module, the signal, the D-SUB male socket, the D-SUB female socket, the impedance matching resistor, the pin header, and the blocking capacitor are all connected through the copper coating on the PCB board.
[0025] In order to extract the HART signal by using a simple circuit and structure, the present application designs an adapter module with an integrated structure. The HART signal is safely extracted through the tee connection of the adapter module with the original safety barrier base plate, the system cable, and the HART acquisition unit, and at the same time, there is no need to replace the safety barrier base plate. An impedance matching resistor is designed on the conversion circuit of the adapter module to adjust the loop impedance. At the same time, by applying a DC blocking capacitor to the horn socket, the signal common ground problem is solved, effectively preventing signal failure problems caused by signal short - circuit of the HART acquisition module.
[0026] A more optimal solution of the present utility model is as follows:
[0027] The horn socket connector is connected to the HART acquisition unit through a flexible cable, and its design specifications meet the requirements of current mainstream brands.
[0028] The adapter module, the impedance matching resistor, the DC blocking capacitor, and the PCB board are encapsulated in the module housing. Two fixing screws are provided on the module housing, and the ends of the fixing screws are connected to the safety barrier base plate to realize the stable connection between the adapter module and the safety barrier base plate, ensuring signal transmission under long - term application conditions.
[0029] Further preferably, the module housing is a rectangular box - shaped structure. The horn socket and the D - SUB male socket are located on the upper surface of the module housing. The D - SUB female socket is located at the bottom of the module housing and the bottom surface of the D - SUB female socket is flush with the bottom surface of the module housing. When the D - SUB female socket is connected to the D - SUB male socket on the base plate, the module housing is tightly connected to the base plate without gaps, which is more convenient for the subsequent installation and connection of the fixing screws.
[0030] The safety barrier base plate is connected to the transmitter, which is the source of signal transmission and acquisition.
[0031] The beneficial effects of the present utility model are as follows:
[0032] (1) The construction speed is fast, and the transformation period is shortened to 10%, minimizing the impact on production operation and manpower requirements during the transformation to the greatest extent;
[0033] (2) Minimize the impact of system transformation on the signal system to the greatest extent. After the transformation, there is no need to conduct a comprehensive test on the system;
[0034] (3) The signal extraction is safe. The failure of the HART acquisition module will not affect the original signal system;
[0035] (4) It has strong versatility and is suitable for most existing safety barrier base plates on the market;
[0036] (5) Both software and hardware can use third - party products, allowing users to select the best among the best, achieving a good user experience and low - cost investment. Brief Description of the Drawings
[0037] The utility model is further described below in conjunction with the accompanying drawings.
[0038] Figure 1 It is a schematic diagram of the overall structure of the utility model;
[0039] Figure 2 This is a schematic diagram of the main structure of the utility model;
[0040] Figure 3 It is a left-side structural schematic diagram of the utility model;
[0041] Figure 4 It is a schematic diagram of the top view structure of the utility model;
[0042] Figure 5 This is a schematic diagram of the structure of the utility model when viewed from above;
[0043] Figure 6 This is a schematic diagram of the circuit principle of the transfer module;
[0044] Figure 7 It is a schematic diagram of the connection process between the adapter module and the safety barrier base plate;
[0045] Figure 8 This is a comparison chart before and after the application of the adapter module on the safety barrier base plate;
[0046] Figure 9 It is a schematic diagram of the connection status between the adapter module and the safety barrier base plate;
[0047] Figure 10 This is the connection diagram of the original safety barrier bottom plate;
[0048] Figure 11 This is a schematic diagram of the connection status between the original safety barrier base plate and the system cable.
[0049] In the figure, 1 D-SUB female socket, 2 D-SUB male socket, 3 horn socket, 4 impedance matching resistor, 5 DC blocking capacitor, 6 module housing, 7 fixing screws, 8 PCB board, 9 safety barrier base plate, 10 base plate D-SUB male socket, 11 system cable, 12 DCS card. DETAILED DESCRIPTION
[0050] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.
[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this utility model belongs. The terms used in the description of this utility model herein are only for the purpose of describing specific embodiments and are not intended to limit this utility model. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.
[0052] The following is a detailed description of this utility model with reference to the accompanying drawings: This embodiment includes an adapter module disposed on the safety barrier base plate 9. The safety barrier base plate 9 is provided with a base plate D-SUB male socket 10. The bottom of the adapter module is provided with a D-SUB female socket, and the D-SUB female socket is plugged into the base plate D-SUB male socket; above the adapter module, there are a D-SUB male socket and a horn socket. The D-SUB female head of the system cable is plugged into the D-SUB male socket, and the end of the system cable is connected to the DCS card; the adapter module contains several signals, and each signal uses two pins. One of the positive signal terminals is connected to the D-SUB male socket through an impedance matching resistor, and the other is connected to the corresponding pin of the horn socket; the negative signal terminal is directly introduced into the D-SUB male socket from the D-SUB female socket and is also connected to the horn socket through a DC blocking capacitor; the adapter module, the signal, the D-SUB male socket, the D-SUB female socket, the impedance matching resistor, the horn socket, and the DC blocking capacitor are all connected through the copper plating on the PCB board.
[0053] For the floor-mounted safety barrier, the industry generally adopts the method of designing and replacing a new floor to safely extract the HART signal; the newly designed floor adds a HART lead-out interface, and the HART signal needs to be paralleled from two lines of the signal loop, and the loop group must meet the requirements of HART modulation.
[0054] The safety barrier base plate 9 is all provided with an integrated socket, and the system cable 11 has a plug matching with this socket, which is used to transfer all the signals on the safety barrier base plate 9 to the system.
[0055] This embodiment takes the Siemens base plate of MTL as an example. The safety barrier base plate 9 is provided with a base plate D-SUB male socket 10, and the system cable 11 for transmitting signals is provided with a D-SUB female head.
[0056] The lower part of the adapter module in this embodiment is a D-SUB female socket, which is used to be plugged into the base plate D-SUB male socket 10 of the safety barrier base plate 9 to introduce the signal into the adapter module.
[0057] The transfer module is equipped with a conversion circuit, including an impedance matching resistor 4 connected in series as required on each signal loop to adjust the loop impedance to meet the impedance requirement of at least 250 ohms for the HART signal. The signal is finally connected to the D-SUB male connector 2 for signal output, which is used to dock with the D-SUB female connector of the original system cable 11, and this is the basic signal transmission function. The positive terminal of each signal is generally directly introduced into the header 3, and the negative terminal of each signal is introduced into the header 3 through a DC blocking capacitor 5. Adding the capacitor is to solve the signal common ground problem, prevent the HART device from interfering with the reference potential of the original system and causing common-mode interference, and also prevent the signal short circuit of the HART acquisition module from affecting the operation safety of the original system.
[0058] The HART signal interface generally uses the header 3, and the connector of the header 3 is connected to the mainstream brand HART acquisition unit through a flexible cable, and its design specifications meet the requirements of the current mainstream brands.
[0059] As shown in the Figure 6 attachment, the transfer module referred to in this embodiment includes the following parts: The transfer module has multiple signals, and each signal uses 2 pins. The signal is introduced into the interface module from the bottom plate D-SUB male connector 10 on the safety barrier bottom plate 9 through the D-SUB female connector 1. One path of the positive terminal of the signal is connected to the D-SUB male connector 2 through the impedance matching resistor 4, and the other path is connected to the corresponding pin of the header 3. The negative terminal of the signal is directly introduced into the D-SUB male connector 2 from the D-SUB female connector 1, and at the same time is connected to the header 3 through the DC blocking capacitor 5. The above components are connected through the PCB board 8, and the entire circuit and devices are encapsulated into a module housing 6. There are also two fixing screws 7 on the housing for fixing the transfer module to the safety barrier bottom plate 9.
[0060] The utility model mainly solves the problem of extracting the HART signal modulated on the 4-20mA current signal of the bottom plate type safety barrier.
[0061] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model, and they should all be covered by the scope of the claims and the description of the utility model.
Claims
1. A three-way HART extraction adapter module, comprising an adapter module arranged on a safety barrier bottom plate (9), the safety barrier bottom plate (9) having a bottom plate D-SUB male socket (10), characterized in that: The adapter module is provided with a D-SUB female socket (1) at the bottom, and the D-SUB female socket (1) is plugged into the D-SUB male socket (10) on the bottom plate; a D-SUB male socket (2) and a horn socket (3) are provided above the adapter module, and the D-SUB female connector of the system cable (11) is plugged into the D-SUB male socket (2), and the end of the system cable (11) is connected to the DCS card (12); the adapter module contains a plurality of signal paths, each signal path uses two pins, and the positive end of the signal is connected through The impedance matching resistor (4) is connected to the D-SUB male socket (2), and the other end is connected to the corresponding pin of the horn socket (3); the negative end of the signal is directly introduced into the D-SUB male socket (2) from the D-SUB female socket (1), and is connected to the horn socket (3) through the DC blocking capacitor (5); the adapter module, signal, D-SUB male socket (2), D-SUB female socket (1), impedance matching resistor (4), horn socket (3) and DC blocking capacitor (5) are all connected through the copper cladding on the PCB board (8).
2. The three-way HART extraction transfer module according to claim 1, characterized in that: The horn socket (3) connector is connected to the HART acquisition unit via a cable.
3. The three-way HART extraction transfer module according to claim 1, characterized in that: The switching module, the impedance matching resistor (4), the DC blocking capacitor (5) and the PCB board (8) are packaged in a module housing (6); two fixing screws (7) are provided on the module housing (6); the ends of the fixing screws (7) are connected to the safety gate bottom plate (9).
4. The three-way HART extraction transfer module according to claim 3, characterized in that: The module housing (6) is a rectangular box-shaped structure, the horn seat (3) and the D-SUB male seat (2) are located on the upper surface of the module housing (6), the D-SUB female seat (1) is located at the bottom of the module housing (6), and the bottom surface of the D-SUB female seat (1) is flush with the bottom surface of the module housing (6).