Patent Application
20070244668
The invention is explained in greater detail below with reference to various exemplary embodiments. An exemplary measured-value acquisition device is illustrated in the single FIGURE.
In the simplest exemplary embodiment, the measured-value acquisition device comprises a function group for measured-value acquisition 10 and a function group for measured-value processing 20 which are physically separate from one another and can be logically connected to one another via a wireless communications link 11, 21. For this purpose a communications terminal 11 can be assigned to the function group for measured-value acquisition 10 and a communications link 21 can be assigned to the function group for measured-value processing 20.
The function group for measured-value processing 20 is connected to a field bus 30. The function group for measured-value processing 20 communicates with a superordinate device via the field bus 30. The function group for measured-value processing 20 can be advantageously supplied with power via the field bus 30 here. In addition, a control and display device 22 can be assigned to the function group for measured-value processing 20.
The function group for measured-value acquisition 10 here encompasses the conversion of a physical value into an adequate electrical value, the signal amplification and the digitization of the measured value. A raw value of the measured value can be provided at the output of the function group for measured-value acquisition 10 and can be forwarded over the wireless communications link 11, 21 to the function group for measured-value processing 20.
The function groups for measured-value acquisition 10 can be located close to the process at the measuring site. In this arrangement, each function group for measured-value acquisition 10 can be supplied with power locally.
In another exemplary embodiment, a battery is provided as the power source for supplying power to the function groups for measured-value acquisition 10. As a result of the limited functionality of the function groups for measured-value acquisition 10, their power consumption can be so low that they can be supplied by a battery, and with long service intervals.
Connected to a wireless transmission, the function groups for measured-value acquisition 10 can now be incorporated in the measured-value acquisition device completely wirelessly. This greatly simplifies their installation close to sensors.
In yet another exemplary embodiment, a device for local power generation is assigned to the function group for measured-value acquisition 10. In this case provision may be made to utilize a primary energy that can be used in the process, such as compressed air for example, the flow energy of which is converted into electrical energy by means of a turbine and a generator. Alternatively, natural primary energy sources, such as sunlight for example, may be used with means for conversion into electrical energy that are known per se. The person skilled in the art will choose a suitable form depending on the primary energy available at the measuring site.
The primary energy supply can be expediently backed up by a battery for bridging breaks in supply or power failures. As a consequence, it is expediently possible to dispense with supply-related maintenance, such as would be required for changing batteries.
The function group for measured-value processing 20 encompasses the complete conditioning of the raw value of the measured value obtained from the function group for measured-value acquisition 10, including linearization and calibration, as well as the communication of the measurement device with a requesting, superordinate device via the field bus 30. In addition, the function group for measured-value processing 20 is responsible for controlling the control and display device 22.
Depending on the type of measured-value acquisition device, further inputs/outputs for local control may be provided, which are then also controlled and operated by the function group for measured-value processing 20.
In yet another exemplary embodiment, it is provided that two or more function groups for measured-value acquisition 10 are assigned to a function group for measured-value processing 20. In this version too, the overall functionality can be performed by the sum of the separated units. It is however advantageous that the function groups for measured-value acquisition 10 may simply be located in the vicinity of the measuring site and that, despite the local installation of said units, only a single function group for measured-value processing 20 is ever required. This has a beneficial effect on the total power consumption.
All power-hungry functions such as, for example, the HART or field bus communications, which require computing power for the signal processing and calibration or the control of a display with backlighting, can be reserved for the function group for measured-value processing 20. The function group for measured-value processing 20 can be located at any point in the vicinity of the function groups for measured-value acquisition 10. Its power can be advantageously provided here via the loop-fed HART or field bus communication.
In yet another exemplary embodiment, a wireless communications link is provided between the function groups for measured-value acquisition 10. In this case, one or more function groups for measured-value acquisition 10 always communicates with the function group for measured-value processing 20 via at least one further function group for measured-value acquisition 10. As a result of this, obstacles 40 that interfere with the direct communication between the function group for measured-value processing 20 and one of the function groups for measured-value acquisition 10 can be advantageously overcome. Consequently, flexibility in the selection of the measuring sites can be further increased. In addition, the availability of such a redundant system can be increased and the system can be more robust with respect to faults.
It will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein.
40 Obstacle
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2006 018 174.3 | Apr 2006 | DE | national |
