EP2616891A1

EP2616891A1 - Field device for determining and/or monitoring a chemical or physical process variable in automation technology

Info

Publication number: EP2616891A1
Application number: EP11763614.2A
Authority: EP
Inventors: Roland Grozinger; Peter KLÖFER
Original assignee: Endress and Hauser SE and Co KG
Current assignee: Endress and Hauser SE and Co KG
Priority date: 2010-09-16
Filing date: 2011-08-31
Publication date: 2013-07-24
Also published as: CN103109246A; WO2012034859A1; US20130176036A1; DE102010040866A1

Abstract

The invention relates to a field device (1) for determining and/or monitoring a chemical or physical process variable in automation technology. Said field device comprises at least one first electronic or electric component (2) and a second electronic or electric component (3), an energy transmission antenna (4) being associated with the first component (2) and an energy reception antenna (5) being associated with the second component (3). A predefined distance range (6) between the two components (2, 3) offsets the first component (2) and the second component (3) relative to each other, said distance range (6) being at least partially filled with a dielectric medium. The energy transmission antenna (4) is designed and/or disposed in such a way as to supply energy to the second component (3) continually or in predefined time intervals.

Description

Field device for determining and / or monitoring a chemical or physical process variable in automation technology

The invention relates to a field device for determining and / or monitoring a chemical or physical process variable in automation technology, wherein the field device has at least one first electronic or electrical component and a second electronic or electrical component. In automation technology, in particular in process automation technology, field devices are often used which serve to detect and / or influence process variables. For the detection of process variables are sensors, such as

Level gauges, flowmeters, pressure and pressure gauges

Temperature measuring devices, pH redox potential measuring devices, conductivity measuring devices, etc., which record the corresponding process variables level, flow, pressure, temperature, pH or conductivity. Actuators, such as valves or pumps, are used to influence process variables

Flow of a liquid in a pipe section or the

Level can be changed in a container. In principle, field devices are all devices that are used close to the process and that provide or process process-relevant information. In the context of the invention, field devices are therefore also understood to mean, in particular, remote I / Os, radio adapters or general devices which are arranged on the field level. A variety of such field devices is provided by the company

Endress + Hauser manufactured and distributed.

In modern process plants, the communication between at least one higher-level control unit and the field devices usually takes place via a bus system, such as Profibus® PA, Foundation Fieldbus® or HART. The bus systems can be designed both wired and wireless. The higher-level control unit is used for process control, process visualization, process monitoring and commissioning and operation of the field devices and is also referred to as a configuration / management system. Programs based on parent

Units run independently, are for example the operating tool

FieldCare of the Endress + Hauser group, the Pactware operating tool, the Fisher-Rosemount AMS operating tool or the PDM operating tool of

Siemens. Operator tools that are integrated into control system applications are the PCS7 from Siemens, the Symphony from ABB and the Delta V from

Emerson. The term 'operation of field devices' in particular the configuration and parameterization of field devices, but also the

Diagnosis for the early detection of errors on the field devices or in the process understood.

By default, individual components of field devices are in the

Automation technology connected via lines and are supplied via the lines with energy. The energy transmission via cable or via wired connection lines has the following disadvantages:

- Wired EMC interference (conducted

electromagnetic compatibility disorders) arrive via the cable or the connecting line directly to the individual

components;

- In order to prevent the carryover of overvoltages between the components in the event of a fault, they must be protected by appropriate power limitation measures. However, these so-called Ex limits have the disadvantage that in normal operation, they account for a large part of the already scarce power

consume. The invention has for its object to propose a field device in which these disadvantages are avoided.

The object is achieved in that the first component of an energy transmitting antenna or transmitting coil and the second component is associated with an energy receiving antenna or receiving coil, wherein between the two components a predetermined distance range consists of the first component and the second component from each other deposited, wherein the distance range is at least partially filled with a dielectric medium, wherein the wireless energy transmission over larger

Distances from an energy transmitting antenna to an energy receiving antenna by means of resonance resonant circuits with the same

Resonant frequency is ausgestalltet, and wherein the energy transmitting antenna is configured and / or arranged so that it supplies the second component continuously or at predetermined time intervals with energy.

The embodiment is considered to be particularly advantageous in that the field device is designed so that it is suitable for use in potentially explosive atmospheres.

The aforementioned disadvantages of a cable-bound

Energy transfer are circumvented by the inventive solution. In particular, according to the invention, line-bound EMC interference is completely eliminated. This is with the known galvanic decoupling due to e.g. conventional transformers with core not completely possible. By contrast, field devices according to the invention have complete EMC and galvanic isolation with regard to the power supply. This facilitates and simplifies the use in the

potentially explosive area, since power-consuming Ex limits can be saved. Furthermore, the invention has the advantage that by the spatial separation automatically also a climatic

Decoupling can be achieved.

Preferably, the technology underlying the energy transmitting antenna and the energy receiving antenna is the WREL technology "Wireless Resonant Energy Link". The current intensive development work on this wireless energy transmission by resonance actually have the goal over, compared to the dimensions described here significantly longer distances and also significantly higher energy from an energy transmitting antenna or transmitting coil to an energy receiving antenna or transmitting coil to transmit , The basic principle of the WREL technology is based on the phenomenon of resonance: A WREL receiver can absorb energy from a magnetic field with a wire coil when it is emitted by a transmitter via a wire coil with the appropriate frequency. Here, the WREL determines

Receiver by its design exactly the desired current and voltage. By means of an inductive coupling of two resonance resonant circuits of an antenna capacitance and a coupling coil via a common magnetic field energy can be transmitted very efficiently. For this purpose, the resonance frequencies of the resonance resonant circuits of the transmitting antennas and the receiving antennas must be coordinated. The resonance frequencies of the resonance resonant circuits are in the megahertz range in order to radiate as little energy as possible into the environment or to influence this environment. Furthermore, the WREL shines

Transmit antenna always only as much energy, as requested by the receiving antenna. Within the response range of the transmit antenna, the position of the receive antenna can be changed without sacrificing the quality of the energy transfer. A similar technique of

Energy transfer is shown, for example, in the publication "Witricity Wireless Energy Transfer", Rico Zanchetti & Luca Costa, HTW Chur, Switzerland. An advantageous embodiment of the field device according to the invention provides that the first component is an electronic terminal compartment designed according to a first type of protection and that the second component is a sensor module or actuator module designed according to a second type of protection. In this case, the sensor module or the actuator module are spaced from the electronics connection space via a dielectric spacer. This spacer is also used for thermal decoupling of electronics connection space and sensor or actuator module. The sensor module or the actuator module has a sensor or an actuator. The power transmitting antenna is associated with the electronics terminal compartment while the power receiving antenna is associated with the sensor module. The power transmission antenna supplies the

Sensor module or the actuator module wirelessly with energy. examples for

Sensors and actuators are already included in the introduction to the description

sufficiently described, so that is omitted at this point on a repetition. Due to the two separate housing chambers, a complete climatic decoupling can be ensured. Alternatively, the second component may be a mainboard, that is, a motherboard following the terminal board. Furthermore, the principle and advantage of wireless energy transfer can also be applied between all printed circuit boards of a complex overall electronics. Of course, the dielectric material may also be air.

Another embodiment relates to the use of the inventive solution in products of the E + H group, which use the Memosens technology. For the purpose of energy supply, for example, a transmitting antenna is assigned to the sensor cable, while the receiving antenna is arranged in the sensor head. In an embodiment of a field device customary in automation technology, the electronics connection space is pressure-resistant, in particular Ex-d, configured while the sensor module is intrinsically safe, in particular Ex-i. In order to guarantee the Ex-i safety, ExBarriers are usually provided which limit the power supply from the terminal compartment to the sensor or actuator module in such a way that, in the event of a fault, no sparking occurs which could lead to an explosion in the outer space. Thus, the power supply is limited, which is usually reflected in a lower measuring rate of the field device. Since continue the

Power is supplied via lines, these are subject to the already described wired EMC interference. By the

Wireless energy transmission according to the invention eliminates these disadvantages. In addition, only the power required by the second component, that is to say the sensor or actuator module, is always transmitted. It is therefore sufficient to design the sensor module or the actuator module such that it only subtracts the maximum permissible power in the potentially explosive area from the energy transmitting antenna. A preferred embodiment of the field device according to the invention proposes that, in addition, the communication between the electronics terminal compartment and the sensor module takes place galvanically separated, e.g. via radio or via a fiber optic. This is already possible and customary today, since virtually no energy is transmitted with pure data communication.

It proves to be particularly suitable if the field device is a radar measuring device for determining the filling level of a filling material in a container. Here is in the electronic terminal compartment sensor electronics for processing / evaluation of the supplied from the sensor element

Measurement data arranged. In the sensor module itself is a

High-frequency module, the high-frequency measurement signals, in particular Microwaves, generated. The high-frequency measurement signals are located in the GHz range. Corresponding level gauges are used by the

Applicant in different forms offered and distributed. An embodiment of the field device according to the invention provides that a plurality of second components are provided, which are supplied with power simultaneously or in series via the energy transmitting antenna. Here, the following mode of operation comes into play: The wireless energy transmission is two or more coupled resonance coils. One of the coils is the energy source or energy transmitter, while the other coil (s) is / are the energy sink (s) or energy receiver (s). The transmitter coil is preferably fed with a high-frequency AC voltage in the order of 10 MHz. Receiver coils that are at a suitable distance from the transmit coil and that have the proper resonant frequency can receive energy from the transmit coil. In this case, only as much energy is transmitted as is currently required by the receiver coil.

On the other hand, no energy is transmitted to receiver coils whose resonance frequency does not match the transmission frequency of the transmission coil.

An advantageous embodiment of the field device according to the invention provides that the field device is assigned a higher-level control unit and that the communication between the field device and the higher-level control unit via at least one adapted to the respective hazardous area connection line is wired. Alternatively, the data transmission can also be inductive, capacitive, optical or wireless. The higher-level control unit is a PLC, a programmable logic controller, or a PCS, a process control system. Corresponding examples are already mentioned in the introduction to the description. It is also proposed that the energy supply of the

Control unit also takes place wirelessly. For this purpose, in addition to the energy transmitting antenna, an energy receiving antenna must be provided in the first component. A corresponding solution is described in the patent application filed on the same day with the present application to the German Patent Office under the title "System with at least one energy transmitting antenna and at least one field device". The disclosure content of this parallel patent application is hereby expressly attributed to the disclosure content of the present patent application, since both can also work in combination.

According to an advantageous embodiment of the field device according to the invention, an energy store is associated with this, which is able to store the energy received by the energy receiving antenna. This has the advantage that even in the case of a short-term disturbance of the energy transmission, the correct function of the field device is guaranteed.

The invention will be explained in more detail with reference to the following figure Fig. 1. 1 shows a field device 1 configured as a level measuring device. The

Level gauge determines the level of a product in a container via a transit time method. Corresponding level gauges have become well known in various embodiments. In general, however, the field device 1 according to the invention serves - as already explained in the introduction to the description - for the determination and / or monitoring of any chemical or physical process variable in the field

Automation technology, especially in process automation technology. The preferred field of application of the field device 1 is the potentially explosive area. The field device 1 has as first component 2 an electronic Connection space and as a second component 3, a sensor module. The electronics connection space 2 contains the sensor electronics 10 for processing and evaluation of the measurement data supplied by the sensor. By doing

Sensor module 3 is an RF module 1 1, which is used to generate high-frequency measurement signals. In the electronics connection space 2, an energy transmission antenna 4 is further arranged. The energy transmission antenna 4 is configured and / or arranged such that it supplies the second component 3 with energy continuously or at predetermined time intervals.

The sensor module 3 is associated with an energy receiving antenna 5 for this purpose. Between the two components 2, 3, a predetermined distance range 6 is provided, which separates the first component 2 and the second component 3 from each other. This distance region 6 is at least partially filled with a dielectric medium. The dielectric material is preferably a plastic, glass or ceramic. However, the dielectric material may simply be air. The purpose of the distance range 6 or the spacer 6 is to thermally decouple the two components 2, 3 from each other. Incidentally, a typical distance between the electronics connection compartment 2 and the sensor module is 5 mm to 20 cm for level gauges.

In a preferred embodiment, the electronics connection compartment 2 is pressure-resistant, in particular Ex-d, configured while the sensor module 3 is intrinsically safe, in particular Ex-i.

The communication between the electronics terminal compartment 2 and the sensor module 3 is carried out either via radio or via a fiber optic 9.

In principle, however, it is also a capacitive, optical or inductive

Data transmission possible. It goes without saying that a power transmission antenna can also supply power to a plurality of different second components 3 - including those of other field devices arranged in the vicinity. Usually, the field devices are connected to a higher-level control unit 7 via a bus system. In FIG. 1, therefore, the system according to the invention is not restricted to a field device 1 and a higher-level control unit 7, but usually with the control unit 7 a plurality of identical or different field devices 1, which are used to control a process plant. The communication between the at least one field device 1 and the higher-level control unit 7 via at least one adapted to the respective hazardous area connection line 8 is wired. Known bus protocols are known in the introduction to the description.

For example, the compound is an elevated one

Casing adapted to safety requirements. Of course, the communication can also be wireless. It is also possible to use the energy over the previously described e.g. WREL technology from the parent control unit 7 to the field devices 1 to transfer. A corresponding system is in the present German patent application parallel patent application with the same filing date

described. The disclosure of this parallel patent application is attributable to the present patent application.

In order to ensure that the field device is still ready for operation even in the event of a short-term power transmission failure, an energy store 12 is provided which stores the energy received by the energy receiving antenna 4 in the sensor module 3 and, if necessary, stores it for

Provides. LIST OF REFERENCE NUMBERS

field device

Terminal compartment / first component

Sensor module / actuator module / second component

Energy-transmitting antenna

Energy receiving antenna

Distance range / distance piece

higher-level control unit

connecting line

management

sensor electronics

RF module

energy storage

Claims

claims

1 . Field device (1) for determining and / or monitoring a chemical or physical process variable in automation technology, wherein the field device comprises at least a first electronic or electrical component (2) and a second electronic or electrical component (3), wherein the first component (2 ) An energy transmitting antenna (4) and wherein the second component (3) is associated with an energy receiving antenna (5), wherein between the two components (2, 3) a predetermined

Distance range (6) consists of the first component (2) and the second

Component (3) from one another, wherein the distance range (6) is at least partially filled with a dielectric medium, wherein a wireless energy transfer by means of resonance resonant circuits over greater distances from an energy transmitting antenna (3) to an energy receiving antenna (4) is configured, wherein the resonant circuit of the receiving antenna (4) and the resonant circuit of the transmitting antenna (3) are designed and arranged so that both the same

Have resonant frequency, and wherein the energy transmitting antenna (4) is configured and / or arranged so that it supplies the second component (3) continuously or at predetermined time intervals with energy.

2. Field device according to claim 1,

wherein the field device (1) is designed so that it is suitable for use in potentially explosive atmospheres.

3. Field device according to claim 1 or 2, wherein it is at the first

Component (2) is a designed according to a first type of protection electronic terminal compartment and wherein it is in the second

Component (3) is a configured according to a second type of protection sensor module or an actuator module, wherein the sensor module (3) or the actuator module from the electronics connection space (2) is spaced, wherein the sensor module (3) or the actuator module has a sensor or an actuator, wherein the energy transmitting antenna (4) is assigned to the electronics connection space, wherein the energy receiving antenna (5) is associated with the sensor module (3) and wherein the energy Transmit antenna (4), the sensor module (3) or the actuator module wirelessly powered.

4. Field device according to claim 3,

wherein the electronics connection space (2) pressure-resistant, in particular Ex-d, is configured and wherein the sensor module (3) intrinsically safe, in particular Ex-i, is formed.

5. Field device according to claim 2, 3 or 4,

wherein the communication between the electronics connection space (2) and the sensor module (3) takes place galvanically isolated, in particular via radio or a fiber optic (9).

6. Field device according to one or more of the preceding claims, wherein the field device (1) is a radar device for determining the filling level of a filling material in a container, wherein in the electronics connection space (2) a sensor electronics (10) for processing / Evaluation of the measurement data supplied by the sensor is arranged and wherein in the sensor module (3) an RF module (1 1) is arranged for generating high-frequency measurement signals.

7. Field device according to one or more of the preceding claims, wherein on the second component (3) further following components are provided, which are supplied either simultaneously via the power transmitting antenna (4) or in series via other transmission antennas present on the additional components with energy ,

8. Field device according to one or more of claims 1 -7, wherein the field device (1) is associated with a higher-level control unit (7) and wherein the communication between the field device (1) and the higher-level control unit (7) is wired via at least one connection line (8) adapted to the respective explosion-endangered area.

9. Field device according to one or more of the preceding claims, wherein an energy store (12) is provided which stores the energy received by the receiving antenna (4) in the sensor module (3).

10. System according to one or more of the preceding claims, wherein it is at the higher-level control unit (7) is a PLC, a programmable logic controller, or a PCS, a process control system.