Device for compatible DCS active and passive acquisition and distributed control system
By introducing a switching module and a digital-to-analog conversion module into the DCS system, combined with a magnetic latching relay, the compatibility problem of active and passive data acquisition in the DCS system is solved, loop self-diagnosis and low-power switching are realized, and interface design is simplified.
Patent Information
- Application Number
- CN202423000597.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-05
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2034-12-05
AI Technical Summary
Existing equipment cannot simultaneously support both active and passive data acquisition methods in DCS, leading to compatibility issues with field communication equipment.
The device employs a first switching module, a second switching module, and a third switching module, combined with a 4-20mA digital-to-analog converter module. By changing the connection relationships within the switching modules, it achieves compatibility with both active and passive acquisition in DCS, and utilizes magnetic latching relays to achieve stable contact and low-power switching.
It achieves compatibility of 4-20mA digital-to-analog converter modules in both active and passive modes, features loop self-diagnosis, simplifies interface design, reduces the number of external interfaces, and lowers power consumption.
Smart Images
Figure CN223757053U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to distributed control system technical field, especially a kind of device and distributed control system for compatible DCS active and passive collection. BACKGROUND
[0002] Current domestic 4-20mA superimposed HART signal circuit is almost applied to all industrial instruments, and this field communication technology can be distinguished as active and passive scheme according to the position of power supply in topology.
[0003] As shown in Figure 1 Active scheme is with additional power supply line (including three-wire system and four-wire system), adopts two-wire system to output current and HART signal form. Transducer and receiver have additional power supply line connected with VCC end, and 4-20mA current collection is through another two lines.
[0004] As shown in Figure 2 Passive scheme adopts external power supply mode, adopts two-wire system interface, needs to insert power supply in loop to make circuit start working. Transducer and receiver only have two lines for 4-20mA current collection, and one of them is powered.
[0005] However, for the different collection forms of field distributed control system (Distributed Control System, DCS), existing equipment cannot support active and passive collection forms simultaneously.
[0006] Therefore, it is an urgent problem to provide a device and distributed control system capable of supporting active and passive collection forms of DCS simultaneously. UTILITY MODEL CONTENT
[0007] Therefore, it is an urgent problem to provide a device and distributed control system capable of supporting active and passive collection forms of DCS simultaneously.
[0008] Based on the above purpose, in the first aspect, the application provides a device for compatible DCS active and passive collection, comprising: first switching module, second switching module, third switching module and 4-20mA digital-analog conversion module.
[0009] The first end of the first switching module is used for connecting with the 4-20mA digital-analog conversion module, the second end is used for connecting with the second end of the second switching module, and the third end is used for inputting.
[0010] The first end of the second switching module is connected with the first end of the third switching module and the 4-20mA digital-analog conversion module, and the third end is used for input or output.
[0011] The second end of the third switching module is connected with the ground, and the third end is used for input or output.
[0012] Optionally, the first switching module, the second switching module and the third switching module each comprise a single-pole double-throw switch.
[0013] Optionally, the single-pole double-throw switch comprises a magnetic latching relay.
[0014] Optionally, the first end of the first switching module is a moving end, the third end of the second switching module is a moving end, and the third end of the third switching module is a moving end.
[0015] Optionally, the first end of the first switching module is connected with the input end of the voltage stabilizer of the 4-20mA digital-analog conversion module, and the first end of the second switching module and the first end of the third switching module are connected with the loop current loop end.
[0016] Optionally, the 4-20mA digital-analog conversion module is further connected with a signal isolator.
[0017] Optionally, the power output end and the ground port of the 4-20mA digital-analog conversion module are connected with the signal isolator.
[0018] Optionally, the signal isolator is further connected with an upper computer.
[0019] Optionally, in the active case, the first end of the first switching module is connected with the third end, the first end of the second switching module is connected with the third end, and the second end of the third switching module is connected with the third end.
[0020] In the passive case, the first end of the first switching module is connected with the second end, the second end of the second switching module is connected with the third end, and the first end of the third switching module is connected with the third end.
[0021] The second aspect further provides a distributed control system, comprising the device for compatible DCS active and passive collection in any one of the first aspect.
[0022] In general, the present application has at least the following beneficial effects:
[0023] The application changes the connection relationship between each end in the first switching module, the connection relationship between each end in the second switching module, and the connection relationship between each end in the third switching module, so that the 4-20mA digital-analog conversion module is compatible with DCS active and passive collection. BRIEF DESCRIPTION OF DRAWINGS
[0024] In the drawings, like reference numerals are used to indicate like elements throughout the several views. The drawings are not necessarily to scale, the emphasis instead being placed upon illustrating the principles of the application. It should be understood that the drawings are merely for purposes of illustration and are not to be construed as limiting the scope of the application.
[0025] Figure 1 A schematic diagram showing an existing active field communication scheme;
[0026] Figure 2 A schematic diagram showing an existing passive field communication scheme;
[0027] Figure 3 A schematic diagram showing a device for compatible DCS active and passive collection provided by an embodiment of the application;
[0028] Figure 4 A schematic diagram showing a passive case of a device for compatible DCS active and passive collection provided by an embodiment of the application;
[0029] Figure 5 A schematic diagram showing an active case of a device for compatible DCS active and passive collection provided by an embodiment of the application. DETAILED DESCRIPTION
[0030] The application will be further described below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related utility model, and not to limit the utility model. In addition, it should be noted that, for ease of description, only the parts related to the utility model are shown in the drawings.
[0031] In a first aspect, the application provides a device for compatible DCS active and passive collection, as shown in Figure 3 including a first switching module 100, a second switching module 200, a third switching module 300, and a 4-20mA digital-analog conversion module 400.
[0032] The first end K11 of the first switching module 100 is connected with the 4-20mA digital-analog conversion module 400, the second end K12 is connected with the second end K22 of the second switching module 200, and the third end K13 is used for input. The first end K21 of the second switching module 200 is connected with the first end K31 of the third switching module 300 and the 4-20mA digital-analog conversion module 400, and the third end K33 is used for input or output. The second end K32 of the third switching module 300 is connected with the ground end, and the third end K33 is used for input or output.
[0033] The third end of the second switching module and the third end of the third switching module are both used for being connected with the DCS module. The first switching module 100 is used for connecting any one of the second end K12 or the third end K13 of the first switching module 100 with the first end K11 of the first switching module 100; the second switching module 200 is used for connecting any one of the first end K21 or the second end K22 of the second switching module 200 with the third end K23 of the second switching module 200; and the third switching module 300 is used for connecting any one of the first end K31 or the second end K32 of the third switching module 300 with the third end K33 of the third switching module 300.
[0034] The first switching module 100, the second switching module 200 and the third switching module 300 all include a single-pole double-throw switch.
[0035] The single-pole double-throw switch includes a magnetic latching relay. The first end K11 of the first switching module 100 is a moving end; the third end K23 of the second switching module 200 is a moving end; and the third end K33 of the third switching module 300 is a moving end.
[0036] The first end K11 of the first switching module 100 is connected with the voltage stabilizer input end VDD1 of the 4-20mA digital-analog conversion module 400, and the first end K21 of the second switching module 200 and the first end K31 of the third switching module 300 are both connected with the loop current loop end Iout.
[0037] The 4-20mA digital-analog conversion module 400 is also connected with the signal isolator 500.
[0038] The power supply output end D1 and the ground port D2 of the 4-20mA digital-analog conversion module 400 are both connected with the signal isolator 500.
[0039] The loop current loop end Iout of the 4-20mA digital-to-analog conversion module 400 can be a pin for the loop current loop, such as a pin LOOP-, etc.; the voltage regulator input end VDD1 of the 4-20mA digital-to-analog conversion module 400 can be a pin for the reference voltage input, such as a pin REGIN, etc.; the power supply output end of the 4-20mA digital-to-analog conversion module 400 can be a pin for the digital power supply output, such as a pin DV DD , etc.; and the ground end can be a ground reference pin, such as a pin GND or a pin COM, etc.
[0040] The signal isolator 500 is also connected to the host computer.
[0041] As shown in FIG. 1, the first switch module 100, the second switch module 200 and the third switch module 300 are connected to the signal isolator 500. Figure 4 As shown in FIG. 2, in the passive case, the first end K11 of the first switch module 100 is connected to the second end K12, the second end K22 of the second switch module 200 is connected to the third end K23, and the first end K31 of the third switch module 300 is connected to the third end K33. Figure 5 As shown in FIG. 3, in the active case, the first end K11 of the first switch module 100 is connected to the third end K13, the first end K21 of the second switch module 200 is connected to the third end K23, and the second end K32 of the third switch module 300 is connected to the third end K33. In the active case, the third end of the second switch module is also connected to the power supply (such as the 24V_IN end in FIG. 4). Figure 5
[0042] Taking the first switch module 100, the second switch module 200 and the third switch module 300 as magnetic latching relays as an example, the embodiments of the present application are further described.
[0043] As shown in FIG. 1, the first switch module 100, the second switch module 200 and the third switch module 300 are connected to the signal isolator 500. Figure 4 The diagram shows the connection method in the passive configuration. In the passive configuration, the first terminal K11 of the first switching module 100 is connected to the second terminal K12, the second terminal K22 of the second switching module 200 is connected to the third terminal K23, and the first terminal K31 of the third switching module 300 is connected to the third terminal K33. The regulator input terminal VDD1 of the 4-20mA digital-to-analog converter module 400 is connected to one end of the DCS module through the first terminal K11 and the second terminal K12 of the first switching module 100, and the second terminal K22 and the third terminal K23 of the second switching module 200. The loop current loop terminal Iout of the 4-20mA digital-to-analog converter module 400 is connected to the other end of the DCS module through the first terminal K31 and the third terminal K33 of the third switching module 300. The loop formed by the two-wire connection between the 4-20mA digital-to-analog converter module 400 and the DCS module uses an additional power supply 600. The third terminal K23 of the second switching module 200 is the positive terminal of the loop, and the third terminal K33 of the third switching module 300 is the negative terminal of the loop.
[0044] like Figure 5 The diagram shows the connection method in the active mode. In the active mode, the transmitter's power supply can be used to establish a loop, with the current eventually returning to the power supply's ground (grounding terminal). This is suitable for industrial instruments powered in the field. In the active mode, the first terminal K11 of the first switching module 100 is connected to the third terminal K13, the first terminal K21 of the second switching module 200 is connected to the third terminal K23, and the second terminal K32 of the third switching module 300 is connected to the third terminal K33. The voltage regulator input terminal VDD1 of the 4-20mA digital-to-analog converter module 400 is connected to the power supply (e.g., the transmitter's power supply) through the first terminal K11 and the third terminal K13 of the first switching module 100. Figure 5 The loop current loop terminal Iout of the 4-20mA digital-to-analog converter module 400 is connected to one end of the DCS module through the first terminal K11 and the third terminal K13 of the second switching module 200. The other end of the DCS module is connected to the ground terminal (e.g., the 24V_IN terminal) through the third terminal K33 and the second terminal K32 of the third switching module 300. Figure 5 Connect the 24V_IN-GND terminal to the DCS module. The loop formed by the two-wire connection between the 4-20mA digital-to-analog converter module 400 and the DCS module can be powered by the transmitter itself. The third terminal K23 of the second switching module 200 is the positive terminal of the loop, and the third terminal K33 of the third switching module 300 is the negative terminal of the loop.
[0045] like Figure 4 and Figure 5As shown, in the active case and the passive case, the power output end and the ground end of the 4-20 mA digital-to-analog conversion module 400 are connected with the signal isolator. The power output pin end (Vdd2 end) and the ground end (Vss end) are equivalent to a set of positive and negative poles of the power supply, which is generated due to the establishment of the 4-20 mA loop of the 4-20 mA digital-to-analog conversion module 400 (the input of the stabilizer input end VDD1 and the output of the loop current loop end Iout). The Vdd2 end for detecting voltage can be added to the power output pin end, and the Vss end for monitoring voltage can be added to the ground end. The condition for the Vdd2 voltage of the Vdd2 end to be generated is that the 4-20 mA loop of the 4-20 mA digital-to-analog conversion module 400 is closed loop communication. Therefore, in the active and passive cases, whether the loop is established can be judged by whether the Vdd2 voltage of the Vdd2 end and the Vss voltage of the Vss end generate voltage values, so as to realize the self-diagnosis function of the loop (the 4-20 mA loop between the 4-20 mA digital-to-analog conversion module 400 and the DCS module).
[0046] The embodiment of the present application has two characteristics: first, the adjustable constant current source realizes digital-to-analog conversion of the 4-20mA digital-to-analog conversion module 400 through SPI (serial peripheral interface). After the loop is established, a voltage (Vdd2 voltage) output can be realized by extracting energy in the loop, and the adjustment of this voltage can be realized by adjusting the circuit parameters. The premise of this voltage is the establishment of the loop, so the loop can be judged by this voltage. Second, stable power supply can be provided for the two-wire passive transmitter, and the generated voltage can also power the active transmitter low-power isolation device to realize signal isolation; second, the two-wire interface is compatible with active 4-20mA and passive 4-20mA. For passive 4-20mA, the positive terminal of the external interface should be connected to the field power supply, that is, the first end K11 of the first switching module 100 should be conductive with the third end K23 of the second switching module 200, so as to be connected with the field power supply; the current is output from the negative terminal, that is, the first end K31 of the third switching module 300 is conductive with the third end K33 of the third switching module 300. For active 4-20mA, the positive terminal of the external interface should be current output, that is, the first end K21 of the second switching module 200 is conductive with the third end K23 of the second switching module 200, so as to output the current to the DCS module; the negative terminal is a current return input interface, that is, the second end K32 of the third switching module 300 is conductive with the third end K33 of the third switching module 300, so as to make the current flow to the ground terminal 24V_IN-GND. Since the active and passive interfaces need to be powered in the compatible case, for the electronic analog switch, since it is impossible to limit the level and wiring mode of the external environment, and the reference ground plane will affect the loop establishment, the analog switch is difficult to meet the requirements. Therefore, the embodiment of the present application realizes the switching on the loop by using a magnetic latching relay, and the relay can realize stable isolation contact and the magnetic latching relay is compatible with the power consumption requirement.
[0047] The embodiment of the present application can realize 4-20mA active and passive switching in the compatible case by changing the connection in the switching module, achieve the goal of active and passive compatibility and interface consistency, and realize the loop self-diagnosis function.
[0048] The embodiment of the present application uses a magnetic latching relay to realize stable conduction resistance and reliable active and passive switching; the power supply output end D1 and the ground port D2 of the 4-20mA digital-to-analog conversion module 400 can realize loop self-diagnosis in the active or passive case; the second switching module 200 and the third switching module 300 realize the compatibility of the two interfaces, and in the passive case, the power supply interface does not need to be added.
[0049] In a second aspect, the application also provides a distributed control system comprising the device for compatible DCS active and passive acquisition according to any one of the first aspect.
[0050] The embodiment changes the connection relationship between the terminals in the first switching module 100, the connection relationship between the terminals in the second switching module 200 and the connection relationship between the terminals in the third switching module 300, thereby realizing the compatibility of the 4-20mA digital-analog conversion module 400 with the DCS active and passive acquisition through the external interface (the second switching module 200 and the third switching module 300). Moreover, the voltage generated by the power output terminal D1 and the grounding terminal D2 can realize the 4-20mA loop detection function, and the self-diagnosis is supported. The existing active and passive switching mainly has three ways: mechanical code switch, analog switch and relay. The advantage of selecting the relay is that the relay is mechanically conductive in nature, and the contact is stable. Further, the selected magnetic latching relay is compatible with low power consumption, has stable low conduction resistance, and can realize liquid crystal configuration switching without manual operation device. The loop establishment is the premise of the voltage generated by the power output terminal D1 and the grounding terminal D2. There are two methods to judge the loop establishment. The first method is to generate power supply through the loop (the method adopted in the application); the second method is to increase the detection element in the loop to realize current detection. The second method can realize the self-checking of the loop current, but increases the circuit cost, increases the difficulty of the board and the area of the line board, and increases the volume of the industrial instrument. Therefore, the two-wire interface selected by the embodiment of the application is simpler for field use, reduces the number of external interfaces, is more concise in judging the loop establishment, and can bring convenience to the board and interface protection.
[0051] It should be noted that:
[0052] In the specification provided herein, a large number of specific details are described. However, it can be understood that the embodiments of the application can be practiced without these specific details. In some examples, well-known methods, structures and techniques are not shown in detail in order not to obscure the understanding of the present specification.
[0053] Similarly, it is to be understood that the embodiments of the application can alternately be phrased or described substantially similarly to what is found in the description of the example embodiments of the application above, with the features of the application being grouped differently without departing from the scope of the application. For example, in the claims below, any of the claims can be read to indicate one or a combination of the features of the application in any possible arrangement and combination, unless otherwise managerial.
[0054] Those skilled in the art will appreciate that the modules in the apparatuses in the embodiments can be adapted and placed in one or more apparatuses other than the embodiments. The modules or units or components in the embodiments can be combined into one module or unit or component, and further can be divided into multiple sub-modules or sub-units or sub-components. Any combination of all the features disclosed in the specification (including the accompanying claims, abstract and drawings), and all the processes or units of any methods or apparatuses so disclosed, can be taken, except that at least some of such features and / or processes or units are mutually exclusive, unless specifically stated otherwise. Each feature disclosed in the specification (including the accompanying claims, abstract and drawings) can be replaced by alternative features serving the same, equivalent or a similar purpose, unless specifically stated otherwise.
[0055] Furthermore, those skilled in the art will appreciate that different embodiments of the application have different features and that the features of one embodiment can be combined with features of another embodiment or can be replaced by features of another embodiment. For example, in the claims below, any of the claims can be read to indicate that the <000000> claimed embodiments can be used in any combination.
[0056] The various component embodiments of the present application can be implemented in hardware, or as software modules running in one or more processors, or in combinations thereof. As will be appreciated by one skilled in the art, a microprocessor or digital signal processor (DSP) can be used in practice to implement some or all of the functionality of some or all of the components in the virtual machine creation system according to embodiments of the present application. The present application can also be implemented as a program of instructions for performing part or all of the methods described herein, e.g., a computer program and a computer program product. Such program of the present application can be stored on a computer readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, or provided on a carrier medium, or in any other form.
[0057] It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and that one skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word 'comprising' does not exclude the presence of elements or steps other than those listed in a claim. The word 'a' or 'an' preceding an element does not exclude the presence of a plurality of such elements. The application can be implemented by means of both hardware and software, and any combination thereof. In a system claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage. The use of relative terms such as 'about', 'approximately','substantially' and the like, in connection with a given numerical value, is intended to mean that the value can vary from the indicated one by a margin of error, which is acceptable in the art.
[0058] The above description is only specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can easily think of various changes or replacements within the technical range disclosed in the present application, and these should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. An apparatus for compatible DCS active and passive acquisition, characterized by, The device comprises: a first switching module, a second switching module, a third switching module and a 4-20mA digital-analog conversion module; the first end of the first switching module is used to be connected with the 4-20mA digital-analog conversion module, the second end is used to be connected with the second end of the second switching module, and the third end is used for input; the first end of the second switching module is used to be connected with the first end of the third switching module and the 4-20mA digital-analog conversion module, and the third end is used for input or output; the second end of the third switching module is used to be connected with a ground end, and the third end is used for input or output.
2. The apparatus for compatible DCS active and passive acquisition of claim 1, wherein, The first switching module, the second switching module and the third switching module all comprise a single-pole double-throw switch.
3. The apparatus for compatible DCS active and passive acquisition of claim 2, wherein, The single-pole double-throw switch comprises a magnetic latching relay.
4. The apparatus for compatible DCS active and passive acquisition of claim 1, wherein, The first end of the first switching module is a moving end; the third end of the second switching module is a moving end; and the third end of the third switching module is a moving end.
5. The apparatus for compatible DCS active and passive acquisition of claim 1, wherein, The first end of the first switching module is connected with the input end of a voltage stabilizer of the 4-20mA digital-analog conversion module, and the first end of the second switching module and the first end of the third switching module are both connected with the loop current loop end of the digital-analog conversion module.
6. The apparatus for compatible DCS active and passive acquisition of claim 1, wherein, The 4-20mA digital-analog conversion module is further connected with a signal isolator.
7. The apparatus for compatible DCS active and passive acquisition of claim 6, wherein, The power output end and the ground port of the 4-20mA digital-analog conversion module are both connected with the signal isolator.
8. The apparatus for compatible DCS active and passive acquisition of claim 6, wherein, The signal isolator is further connected with an upper computer.
9. The device for compatible DCS active and passive acquisition according to claim 1, wherein, in the active case, the first end of the first switching module is connected with the third end, the first end of the second switching module is connected with the third end, and the second end of the third switching module is connected with the third end; in the passive case, the first end of the first switching module is connected with the second end, the second end of the second switching module is connected with the third end, and the first end of the third switching module is connected with the third end.
10. A distributed control system, characterized by The device for compatible DCS active and passive acquisition according to any one of claims 1 to 9.