Overhead HART (highway addressable remote transducer) extraction switching module

Abstract

The utility model relates to the technical field of safety barrier signal acquisition, in particular to an overhead HART (Highway Addressable Remote Transducer) extraction switching module. The overhead HART extraction switching module comprises a switching module which is mounted above the side of a guide rail type safety barrier in an overhead manner, and is characterized in that a system side outgoing line is led out from the bottom of the switching module to be connected with an inner side terminal of the guide rail type safety barrier; the switching module is provided with an ox horn seat, a plurality of paths of signals and two wiring terminals corresponding to each path of signals; one path of the signal positive end is connected to the wiring terminal through the impedance matching resistor, and the other path is connected to the corresponding pin of the ox horn seat; and a signal negative end is directly led into the wiring terminal from a system side outgoing line, and is connected to the ox horn seat through the blocking capacitor. According to the utility model, the contradiction that the transformation space of the safety barrier HART is insufficient is solved; the position of the original system side multi-core cable is not changed, and no outgoing line needs to be added; the influence of system transformation on the signal system is reduced to the maximum extent, and overhaul and maintenance are convenient after transformation.

Description

Technical Field

[0001] The utility model relates to the technical field of safety barrier signal acquisition, and particularly relates to an overhead HART extraction transfer module. Background Art

[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 relatively 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 relatively high patent licensing fee for using this technology, resulting in a relatively 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 all prefer to select non-HART models during system selection.

[0004] In addition, some instrument manufacturers have a relatively simple HART function in instrument design because they do not deeply understand the HART protocol, and the utilization value of data transmission is not high. Moreover, in the early years, factories did not have requirements for equipment management systems, 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 state 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 transformation time to start over. Replacing with HART-supporting cards of 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 new problem put forward by the process control industry.

[0006] The input and output impedances of 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.

[0007] In this case, there are the following technical routes for HART acquisition transformation:

[0008] (1) Directly replace the DCS card with HART function of the same brand and use the equipment management software of the DCS manufacturer;

[0009] (2) Directly replace the DCS card with HART function of the same brand and use a third-party professional device management software;

[0010] If replacing the DCS card with HART function of the same brand, there are the following disadvantages:

[0011] 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 renovation projects, the selection of equipment is exclusive, and the price can only be negotiated one-on-one, and it is impossible to conduct bidding and price comparison, resulting in the cost of replacing the cards approaching the hardware investment of the original entire system;

[0012] b) Limited software selection: DCS brands focus on process control data processing and do not have an advantage in factory equipment 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;

[0013] c) Slow acquisition speed: Since the card undertakes both process data acquisition and HART data acquisition functions, 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 with thousands of instruments once, which greatly affects the user experience.

[0014] (3) Adopt a third-party HART acquisition device for independent HART data management and cooperate with a third-party device management software; This is the optimal solution recognized by the instrument technology community.

[0015] This solution, that is, installing a HART signal separation board to lead out the HART signal, faces the following problems:

[0016] a) Process control systems using rail-mounted safety barriers account for a relatively large proportion, about half of chemical and petrochemical plants. The components in the original device cabinet are densely packed. After years of operation and several renovations, the remaining reserved space is very limited, and there is no place to install the new HART separation module nearby;

[0017] b) If the HART separation module is installed on the side of the cabinet, the length of the original system-side cable is not enough. Removing and replacing the new cable is more work for the system than constructing a new device. Moreover, after several years of operation, there are already significant differences between the drawings and the actual objects of many devices. Commissioning after renovation is time-consuming and laborious. It is necessary to conduct re-point testing and joint debugging on the system, which requires a lot of manpower, has a long renovation cycle, and brings certain risks.

[0018] Therefore, how to solve the problem of fast signal separation is an urgent problem to be solved in the current industry. Summary of the Invention

[0019] In order to make up for the deficiencies of the prior art, the utility model provides an overhead type HART extraction and transfer module that utilizes the effective space, does not change the position and direction of the cables on the system side, is connected in series between the existing safety barrier and the system cable, and safely extracts the HART signal while the original signal is transferred and passes through normally.

[0020] The utility model is realized through the following technical solutions:

[0021] An overhead type HART extraction and transfer module includes a transfer module overhead-mounted above the side of a rail-mounted safety barrier. The system-side lead-out wire is led out from the bottom of the transfer module and connected to the inner terminal of the rail-mounted safety barrier. A horn socket, several signals, and two wiring terminals corresponding to each signal are arranged on the transfer module. One path of the positive signal terminal is connected to the wiring terminal through an impedance matching resistor, and the other path is connected to the corresponding pin of the horn socket. The negative signal terminal is directly introduced into the wiring terminal from the system-side lead-out wire and is also connected to the horn socket through a DC blocking capacitor. The final wiring terminal of the signal is connected to the terminal of the DCS card through a system-side multi-core cable. The transfer module, the signal, the wiring terminal, the impedance matching resistor, the horn socket, and the DC blocking capacitor are all connected through the copper coating on the PCB board. The horn socket connector is connected to the HART acquisition unit through a flexible cable.

[0022] The transfer module, the horn socket, the wiring terminal, and the PCB board are encapsulated in the module housing. The module housing is erected above the side of the rail-mounted safety barrier through a mounting bracket, and the module housing is rotatably connected to the mounting bracket.

[0023] On the basis of the method of generally connecting a transfer module in series on the system side when extracting the HART signal, the utility model is overhead-mounted above the rail-mounted safety barrier, a HART lead-out interface is configured on the transfer module, and the loop impedance is adjusted to meet the requirements of HART modulation. In addition, the negative signal terminals are all introduced into the horn socket through DC blocking capacitors. Adding DC blocking capacitors is to solve the problem of signal common ground, prevent the HART device from interfering with the original system reference potential and causing common-mode interference, and also prevent the signal short circuit of the HART acquisition block from affecting the operation safety of the original system. In addition, for the convenience of later maintenance and repair of the safety barrier, the module housing is rotatably connected to the mounting bracket.

[0024] A more optimal technical solution of the utility model is:

[0025] Two fixing screws for connecting the mounting bracket are arranged on the module housing. When overhauling, loosen the inner fixing screw, and the module housing can be rotated 90 degrees to stand up, so that the rail-mounted safety barrier is completely exposed, facilitating the overhaul of the waist line thereof.

[0026] Further preferably, due to the limited cabinet space of the original design, the module housing is a long strip structure, and the module housing slightly covers the outlet of the system side lead-out line of the guide rail type safety barrier to achieve compactness of the structural arrangement.

[0027] Further preferably, the mounting bracket is a U-shaped plate frame structure, with a mounting hole arranged at the bottom and fixing holes opened at both symmetrical side ends, and the overall fixation is achieved by connection with the ground through screws and rivets.

[0028] The adapter module is provided with two HART interface headers, and the line sequences of the two headers are opposite, one sequence is channel 1-16, and the other sequence is channel 16-1, for adapting to different installation directions.

[0029] The adapter module is installed in the gap between the guide rail safety barrier and the junction duct, and the modular structure design enables the rapid extraction of the HART signal.

[0030] The guide rail type safety barrier is connected with a transmitter, which is the transmission and detection source of the signal.

[0031] The beneficial effects of the utility model are as follows:

[0032] (1) Solved the contradiction of insufficient space for safety barrier HART transformation;

[0033] (2) The position of the multi-core cable on the original system side remains unchanged, and no additional lead wires are required;

[0034] (3) Minimize the impact of system transformation on the signal system and facilitate maintenance after transformation;

[0035] (4) The construction speed is fast, and the transformation period is shortened to 20%, minimizing the impact of the transformation on production operations and manpower requirements;

[0036] (5) Built-in lead wires ensure signal sampling safety, and failure of the HART acquisition module will not affect the original signal system;

[0037] (6) It is highly versatile and suitable for most control systems with rail-type safety barriers on the market;

[0038] (7) Both software and hardware can be third-party products, and users can choose the best from the best to achieve a good user experience and low-cost investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The utility model is further described below in conjunction with the accompanying drawings.

[0040] Figure 1 It is a structural schematic diagram of the utility model;

[0041] Figure 2This is a schematic diagram of the circuit principle of the transfer module;

[0042] Figure 3 This is a schematic diagram of the connection between the adapter module and the guide rail safety barrier;

[0043] Figure 4 It is a schematic diagram of the connection status between the transfer module and the guide rail safety barrier;

[0044] Figure 5 This is a schematic diagram of the original state of the rail-type safety barrier;

[0045] Figure 6 Schematic diagram of the state after the rail-type safety barrier is equipped with an adapter module;

[0046] Figure 7 Schematic diagram of the maintenance status of the rail-type safety barrier after the adapter module is installed;

[0047] Figure 8 The connection diagram before the transformation is that the inner side incoming lines of two rows of rail-type safety barriers share a common junction trough mode;

[0048] Figure 9 Schematic diagram of the connection after the transformation of the two rows of rail-type safety barriers with a common junction trough for the inner side incoming lines;

[0049] Figure 10 This is a connection diagram before the transformation of the inner side incoming wires of two rows of rail-type safety barriers using a single junction trough mode;

[0050] Figure 11 This is a schematic diagram of the connection after the two rows of rail-type safety barriers are modified to use a separate bus duct mode for the incoming lines on the inside.

[0051] In the figure, 1 is the adapter module, 2 is the terminal block, 3 is the horn socket, 4 is the impedance matching resistor, 5 is the DC blocking capacitor, 6 is the system side lead wire, 7 is the guide rail type safety barrier, 8 is the PCB board, 9 is the system side multi-core cable, 10 is the transmitter, 11 is the DSC card, 12 is the mounting bracket, and 13 is the fixing screw. DETAILED DESCRIPTION

[0052] 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.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0054] The utility model is described in detail below in conjunction with the accompanying drawings: This embodiment includes an adapter module 1 installed overhead on the side of a guide rail safety barrier 7, and the system side lead wire is connected to the inner terminal of the guide rail safety barrier from the bottom of the adapter module 1; a bullnose socket 3, several signals and two wiring terminals 2 corresponding to each signal are provided on the adapter module 1; one positive end of the signal is connected to the wiring terminal 2 through an impedance matching resistor 4, and the other end is connected to the corresponding pin of the bullnose socket 3; the negative end of the signal is directly introduced into the wiring terminal 2 from the system side lead wire 6, and is connected to the bullnose socket 3 through a DC blocking capacitor 5; the final signal wiring terminal is connected to the terminal of the DCS card 11 through a system side multi-core cable 9; the adapter module 1, the signal, the wiring terminal 2, the impedance matching resistor 4, the bullnose socket 3 and the DC blocking capacitor 5 are all connected through the copper clad connection on the PCB board 8; the bullnose socket 3 connector is connected to the HART acquisition unit through a flat cable.

[0055] The new adapter module 1 used in this invention is installed overhead on the side of the rail-type safety barrier 7. Due to the limited cabinet space of the original design, the adapter module 1 is made into a long strip, slightly covering the wiring terminals on the side of the safety barrier system. In order to facilitate the maintenance and repair of the safety barrier in the later stage, the entire adapter module 1 is designed to be a rotatable structure. When it is repaired, it is rotated 90 degrees and erected to fully expose the rail-type safety barrier 7.

[0056] The lower part of the adapter module 1 is the lead-out harness, which is connected to the inner terminal of the guide rail type safety barrier 7 to introduce the signal into the adapter module 1.

[0057] The adapter module 1 is provided with a conversion circuit, including: each signal loop is connected in series with an impedance matching resistor 4 as required, which is used to adjust the loop impedance to meet the HART signal's minimum impedance requirement of 250 ohms; the signal is finally connected to the terminal for signal output, which is used to connect with the system-side multi-core cable 9 from the system, which is a basic signal transmission function. The positive end of each signal is generally directly introduced into the horn socket 3, and the negative end of the signal is introduced into the horn socket 3 through the DC isolation capacitor 5; adding capacitors is to solve the signal common ground problem, prevent HART equipment interference from affecting the original system reference potential, and cause common mode interference, and also prevent the HART acquisition module signal from being short-circuited and affecting the operating safety of the original system.

[0058] The HART signal interface generally uses a horn socket 2. The horn connector is connected to the HART acquisition unit of the mainstream brand through a flat cable, and its design specifications meet the requirements of the current mainstream brands. This adapter module 1 is configured with two HART interface horn sockets 3, and the wire sequence is exactly opposite. One sequence is channels 1-16, and the other sequence is channels 16-1, which is used to adapt to different installation directions.

[0059] The entire circuit and components of the adapter module 1 are encapsulated in a module housing. There are also two fixing screws 13 on the module housing, which are used to fix the adapter module 1 to the mounting bracket 12. Loosen the inner screw, and the adapter module 1 can be rotated 90 degrees upright to facilitate the maintenance of the waistline circuit of the rail-mounted safety barrier 7.

[0060] The adapter module 1 is a miniaturized modular overhead structure for quickly extracting HART signals. It is installed in the gap between the rail-mounted safety barrier 7 and the cable tray; it is a simple modular product that utilizes limited space without changing the position and direction of the cables on the system side. It is connected in series between the existing rail-mounted safety barrier 7 and the system cable. While the original signal is transferred and passed normally, the HART signal is safely extracted; a certain resistance value is inserted into the system-side loop to adjust the internal impedance; directly tapping the signal from the DCS will cause safety risks, disrupt the common ground potential, increase the common-mode interference, and perform DC isolation processing on the signal.

[0061] This utility model mainly solves the problem of extracting the HART signal modulated on the 4-20mA current signal of the rail-mounted safety barrier 7.

[0062] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present utility model, rather than to limit it; although the present 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 present utility model, and they should all be covered by the scope of the claims and the description of the present utility model.

Claims

1. An overhead HART extraction adapter module, comprising an adapter module (1) overhead mounted above a guide rail safety barrier (7), characterized in that: The bottom of the transfer module (1) leads out a system-side lead wire to connect to the inner terminal of the rail-mounted safety barrier; a horn socket (3), several signals, and two wiring terminals (2) corresponding to each signal are arranged on the transfer module (1); one path of the positive signal terminal is connected to the wiring terminal (2) through an impedance matching resistor (4), and the other path is connected to the corresponding pin of the horn socket (3); the negative signal terminal is directly introduced into the wiring terminal (2) from the system-side lead wire (6), and at the same time is connected to the horn socket (3) through a DC-blocking capacitor (5); the final wiring terminal of the signal is connected to the terminal of the DCS card (11) through a system-side multi-core cable (9); the transfer module (1), the signal, the wiring terminal (2), the impedance matching resistor (4), the horn socket (3), and the DC-blocking capacitor (5) are all connected through the copper coating on the PCB board (8); the connector of the horn socket (3) is connected to the HART acquisition unit through a flexible cable; The transfer module (1), the horn socket (3), the wiring terminal (2), and the PCB board (8) are encapsulated in the module housing, and the module housing is erected above the side of the rail-mounted safety barrier (7) through the mounting bracket (12), and the module housing and the mounting bracket (12) are rotatably connected.

2. The overhead HART extraction and transfer module according to claim 1, wherein: Two fixing screws (13) for connecting the mounting bracket (12) are arranged on the module housing.

3. The overhead HART extraction and transfer module according to claim 2, wherein: The module housing is in a long strip structure, and the module housing slightly covers the outlet of the system-side lead wire (6) of the rail-mounted safety barrier (7).

4. The overhead HART extraction transfer module according to claim 2, wherein: The mounting bracket (12) is in a U-shaped plate frame structure, with mounting holes provided at the bottom and fixing holes provided at both symmetric side ends.

5. The overhead HART extraction transfer module according to claim 1, wherein: Two HART interface horn sockets (3) are arranged on the transfer module (1), and the wire sequences of the two horn sockets (3) are opposite. One sequence is channels 1-16, and the other sequence is channels 16-1.

6. The overhead HART extraction and transfer module according to claim 1, characterized in that: The transfer module (1) is installed in the gap between the rail-mounted safety barrier (7) and the cable tray.

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