Device and method for wireless detection and optical reproduction of the operating state of a field device, and field device with such a device

Abstract

A detection and playback device (5) for wireless detection and optical playback of the operating state of a field device (1) in which the operating state is indicated by optical signaling means (3) characterized in that the device (5) has at least one optical detection means (7) for detection of at least one optical state information and at least one optical playback device (9) for playback of the detected state information, and the detection and playback device (5) is coupled to a housing of the field device (1) or is integrally formed with it.

Description

The present invention relates to a device and a method for wirelessly detecting and optically displaying the operating state of a field device, and to a field device with such a device. In process automation technology, field devices are frequently used to detect and / or influence process variables. Examples of such field devices include level gauges, limit level gauges, density gauges, and pressure gauges with sensors that detect the corresponding process variables: level, limit level, density, or pressure. These field devices are often connected to higher-level units, such as control systems or monitoring units. These higher-level units are used for process control, process visualization, and / or process monitoring. Field devices known from the prior art typically consist of a housing, a sensor, and an electronic unit located within the housing. Power and / or signal transmission between field devices and higher-level units often follows the well-known 4 mA to 20 mA standard, in which a 4 mA to 20 mA current loop or a two-wire connection is established between the field device and the higher-level unit. In addition to analog signal transmission, measuring devices can also transmit or receive further information to or from the higher-level unit using various other protocols, particularly digital ones. Examples include the HART protocol and the Profibus PA protocol. The electronic unit of such a field device typically features various status indicators, particularly status lights, which are usually implemented as LEDs. These status indicators provide information about, for example, the device's power supply, a device failure, its status, or binary switching states. The NAMUR Recommendation NE 107, "Self-Monitoring and Diagnostics of Field Devices," dated April 10, 2017, regulates the standardized use of such status lights. The "NAMUR - Interest Group for Automation Technology in the Process Industries," or NAMUR for short, is an advocacy group representing users of measurement and control technology in the chemical industry. One of its goals is to define minimum requirements for devices and systems. In this context, NAMUR issues recommendations that define these minimum requirements. There is increasing interest in making such status indicators readable not only in a process control room or directly at the field device, but also from a greater distance in the field. In the current state of the art, radio modules exist for this purpose, transmitting information about the device's status and other data to a corresponding receiver. However, a disadvantage of this solution is that the receiver must be paired with the radio module to ensure communication. Furthermore, the receiver must be within range of the radio module, otherwise communication is impossible. Radio modules also offer opportunities for third parties to intercept radio communications or use them to manipulate the device. Additionally, the operation of radio modules is sometimes very energy-intensive, so that, for example, in two-wire devices, the energy available via the 4-20 mA current loop is often insufficient. Further state of the art is known from US 2004 / 0032504 A1, EP 1 584 898 A1 and DE 10 2005 054 948 B4. This is where the present invention comes in. The object of the present invention is to provide a device for the simple and clearly visible display of information on the operating status of field devices and to create a possibility for retrofitting older field devices. This problem is solved by a device having the features of claim 1. An inventive device for wireless detection and optical reproduction of the operating state of a field device, in which the operating state is indicated by optical signaling means, is characterized in that the device has at least one optical detection means for detecting at least one optical state information and at least one optical reproduction device for amplified reproduction of the detected state information. In this way, the status information of the field device can be acquired and optically amplified without complex wiring. Optical display devices that offer increased luminous flux and / or a greater number of emission directions are particularly preferred. A particularly simple design is achieved if at least one detection element is an RGB sensor. Alternatively, short-range, low-power wireless interfaces can also be used. The use of RGB sensors enables simple, cost-effective and reliable detection of the condition, i.e. in particular the color, light intensity and blinking frequency of status lights, such as LEDs, arranged on an electronic module. The playback device can be designed as a light source, preferably a light-emitting diode (LED), in particular a multicolor LED or organic light-emitting diode (OLED). It is preferred that the playback device can only reproduce one piece of status information at a time. While this necessitates prioritization and, if necessary, selection between the acquired information, the reproduction of a single signal can be performed with correspondingly high intensity and be clearly visible. To prioritize the status information displayed by the field device, the detection means are preferably designed to capture color information and / or the flashing frequency of the optical signaling devices. Additionally, information is stored that allows for prioritization. Since the status information usually has a unique encoding, i.e., each piece of information to be displayed is assigned a unique color and / or flashing frequency and / or position, this allows for the unique identification of the status information and thus for prioritization. The detection means are advantageously designed to detect the position of the optical signaling means. The position of the signaling devices can be detected by the device having a plurality of detection devices assigned to the optical signaling devices, their positions being, for example, adapted to the positions of the optical signaling devices of the measuring instrument. With a defined orientation of the device relative to the field device, in the simplest case, a detection device can be arranged opposite each signaling device, thus ensuring a unique assignment. Such an assignment can also be made by means of fiber optic cables, which are arranged between the signaling devices to be detected and the respective assigned detection device. The device preferably has a control circuit to which the at least one optical detection circuit is connected and which, when several signaling means are detected simultaneously, selects a signaled status information depending on the color and / or position and / or flashing frequency and supplies this to the playback means. In order to enable a large-area and multi-directional reproduction of the status information, the optical signaling means can be coupled with a light guide and / or a diffusion device, which are designed such that an optical reproduction preferably takes place with an area of ​​at least 10 cm2 and a luminous flux of at least 10 lumens. Preferably, the optical representation takes place in at least two spatial directions, preferably in the axial and radial directions of a cylinder. For this purpose, the light guide and / or the diffusion device can be cylindrical and configured for the corresponding light emission. The acquisition and playback device can, in particular, have its own power supply, especially wireless power supply, e.g., in the form of inductive coupling and / or an integrated energy storage device and / or an energy harvester. In this way, the acquisition device can be designed to be energy self-sufficient and can be used independently of the energy management of the underlying field device. A field device according to the invention for measuring technology, in particular a level, limit level, density or pressure measuring device in which the operating state is indicated by optical signaling means and which has a device for wireless detection and optical reproduction of the operating state, is characterized by a device designed according to the above description for wireless detection and optical reproduction of the operating state. Such a field device may in particular include a conventional electronic unit which signals the operating state of the field device in a conventional manner, wherein a device for wireless detection and optical reproduction of the operating state is integrated into the field device. An inventive method for wirelessly detecting and optically displaying the operating state of a measuring device, in particular a field device, in which the operating state is indicated by optical signaling means, is characterized by the following successive steps: - optical detection of an operating state by detecting at least one optical state information and - optical display of the detected state information by means of an optical display device. Preferably, the captured information is prioritized before optical display, and then the status information with the highest priority is displayed. Prioritization is preferably based on the position and / or color and / or blinking frequency of the captured status information. The present invention is explained in more detail below with reference to an exemplary embodiment and the accompanying figure. Figure 1 shows a schematic sectional view of a field device with a apparatus according to the present application. Fig. 1 shows a schematic sectional view of a field device 1, which is equipped with a detection and playback device 5, hereinafter referred to as the detection device for the sake of simplicity. The field device 1 is essentially constructed like a conventional field device known from the prior art. It comprises an electronic module 15 arranged in a housing 13, which can, for example, perform measured value processing. Typically, the electronic module 15 is connected on its underside to a sensor for detecting physical quantities and has on its upper side, i.e., at an end opposite the sensor, a display device or a display and input device. The display device or display and input device can be configured differently and is essentially known from the prior art. In the prior art, the housing is closed at the top with a cover adapted to the respective display or display and input device. Thus, when using a display device, the cover may simply have a viewing window, while for additional input options, corresponding interfaces, e.g., buttons or the like, must be provided. In the present embodiment, the electronic module 15 has three optical signaling means 3, which are designed as conventional light-emitting diodes. The housing 13 is not closed at the top with a conventional cover, but with the detection device 5. In this case, the detection device 5 is arranged in a receptacle designed as a cover for the housing 13, but it can also itself be designed as a cover or be integral with the housing 13. With such an arrangement, it is also possible to perform cover detection and thus ensure safe operation. In the present embodiment, the detection device 5 has three optical detection means 7 designed as RGB sensors, i.e., optical sensors that enable color discrimination, which are arranged on a side of the detection device 5 oriented towards the signaling means 3 of the electronic module 15. The RGB sensors 7 are arranged such that unobstructed optical detection of the status information displayed by the signaling means 3 is possible. This can be achieved by a clear line of sight or by suitable optical fibers (not shown) arranged between the signaling means 3 and the detection means 7. Furthermore, each detection device 7, in this case an RGB sensor, is assigned to each signaling device 3, in this case an LED. In this context, assignment means that it is clearly identifiable from which signaling device 3 a signal detected by the detection device 7 originates. This can be achieved, for example, by spatially opposing arrangements or by signal assignment using the aforementioned optical fibers. The detection device 5 further comprises an electronic unit 17, by means of which further processing of the detected signals as well as, if necessary, prioritization of the signals based on the underlying state information and selection of state information for playback based on the prioritization takes place. The status information is displayed by means of a display device 9 designed as an LED, which in this embodiment is coupled to a light guide 11. The LED 9 is oriented in the axial direction A and would thus nominally only emit light in this direction under a predetermined beam cone. The light guide 11, which in this case increases the emitting area in the axial direction A and also enables emission in the radial direction R, ensures a clearly visible display of the status information. The detection and playback device 5 shown in Fig. 1 for wireless detection and optical playback of the operating state of the field device 1 thus optically detects the operating state signaled by the LEDs 3 by detecting and evaluating the optically signaled state information. The detected signals are further processed in the electronic unit 17, in particular prioritized, whereby the state information of the highest priority is then displayed by means of the optical playback device 9. A particular advantage of the acquisition and playback device 5 of the present application is that it can be used both in new field devices and is suitable for use with existing field devices. Existing devices can thus be retrofitted. Reference symbol list 1 Field device 3 Optical signaling and playback devices 5 Detection device 7 Optical detection device 9 Playback device / LED / OLED 11 Diffuser / Light guide 13 Housing 15 Electronic module 17 Electronic unit, control circuit A Axial direction R Radial direction

Claims

A detection and playback device (5) for wireless detection and optical playback of the operating state of a field device (1) in which the operating state is indicated by optical signaling means (3), characterized in that the device (5) has at least one optical detection means (7) for detecting at least one optical state information and at least one optical playback device (9) for playback of the detected state information, and the detection and playback device (5) is coupled to or integrally formed with a housing of the field device (1). Device (5) according to claim 1, characterized in that the detection means (7) is designed as an RGB sensor. Device (5) according to claim 1 or 2, characterized in that the playback device (9) is designed as a light source, preferably a light-emitting diode, in particular a multi-color light-emitting diode or an organic light-emitting diode. Device (5) according to one of the preceding claims, characterized in that the detection means (7) are designed to detect color information and a flashing frequency of the optical signaling means (3). Device (5) according to one of the preceding claims, characterized in that the detection means (7) are designed to detect a position of the optical signaling means (3). Device (5) according to one of claims 1 to 4, characterized in that the device (5) has a plurality of detection means (7) which are assigned to the optical signaling means (3) and whose positions are adapted to positions of the optical signaling means. Device (5) according to one of the preceding claims, characterized by a control circuit (17) to which the at least one optical detection circuit (7) is connected and which, when simultaneously detecting several signaling means (3), selects information depending on the color and / or position and / or flashing frequency and supplies this information to the playback means (3). Device (5) according to one of the preceding claims, characterized in that the optical signaling means (3) are coupled with a light guide (11) and / or a diffusion device, which are designed such that an optical reproduction is achieved with an area of ​​at least 10 cm2 and a luminous flux of at least 10 lumens. Device (5) according to one of the preceding claims, characterized in that the optical reproduction (3) takes place in at least two spatial directions, preferably in the axial direction (A) and radial direction (R) of a cylinder. Device (5) according to one of the preceding claims, characterized in that the device (5) comprises a wireless power supply module and / or an energy storage device. Field device (1) of the measuring technology, in particular level, limit level, density or pressure measuring device with a device (5) for wireless detection and optical reproduction of the operating state according to one of the preceding claims. Method for wireless detection and optical reproduction of the operating state of a measuring device in which the operating state is indicated by optical signaling means (3) with a device according to one of the preceding claims 1 to 10, characterized by the following steps: optical detection of an operating state by detecting at least one optical state information and optical reproduction of the detected state information by means of an optical reproduction device. Method according to claim 12, characterized by prioritizing the acquired information before playback and playback of the state information with the highest priority. Method according to claim 13, characterized in that the prioritization is based on a position and / or color and / or blinking frequency of the detected status information.

Images