METHOD FOR OPERATING A FLOWMETER AND FLOWMETER

Description

[0001] The invention is based on a method for operating a flowmeter, wherein the flowmeter has at least one diagnostic unit, a counter unit, and a memory unit with at least one memory. The counter unit determines at least the total volume of a fluid passing through the flowmeter during a measuring process, and the counter unit is operated for the duration of a time-limited measuring process, wherein the diagnostic unit detects at least one faulty or fault-free state of the flowmeter. Furthermore, the invention is also based on a flowmeter with the aforementioned properties.

[0002] Field devices in general are used in process and automation technology as actuators or sensors to determine process variables, whereby the information determined by the field device is either used to control or regulate the process or is made available to the process and / or the user in another way, for example by being visually displayed.

[0003] To ensure error-free measurement values, field devices are subject to particularly stringent requirements in terms of their functional reliability / error susceptibility, as well as their diagnostic capabilities. If a malfunction occurs, it is crucial for assessing the quality of the measured values ​​determined by the field device that the user is informed of the malfunction, also so that they can take appropriate measures to rectify the problem.

[0004] It is therefore known from the state of the art to operate field devices with self-monitoring and / or self-diagnosis, which ensures that in the event of a malfunction, this is immediately communicated to the user so that he or she can assess the quality of the measured values ​​output.

[0005] The present invention relates in detail to a method for operating a flowmeter, which can be used in particular as a field device. According to the invention, the flowmeter comprises a counter unit which, directly or indirectly, for example from the measured values ​​of the measured variables mass flow and density of a fluid, determines a measured value for the current volume passing through the flowmeter and, in addition, also determines, by summation, the total volume passing through the flowmeter during a time-limited measuring process. By specifying the total volume, every point in time during the measuring process can be precisely determined. In this respect, a chronological mapping of the measuring process based on the total volume is possible.

[0006] The flowmeter's diagnostic unit detects at least one faulty or fault-free state of the flowmeter. Faulty states include, for example, defects in the electronics, (illegal) configuration changes, exceeding or falling below the operating temperature, wear, excessive vibration or shock loads, etc. A list of faulty states of field devices is provided in the NAMUR Recommendation NE 107.

[0007] DE 10 2007 026 244 A1 discloses a method for creating an error profile for a field device, in particular for a flowmeter. The error profile can be defined by the user for each specific application via an interface. The defined error profile is stored in a memory, and error messages selected by the user are output by the field device when they occur. Document DE 10 2010 044 184 A1 discloses a method for creating a diagnosis for a field device in a system comprising a plurality of field devices connected to one another in communication. A diagnostic message is automatically generated by the field device and evaluated according to a validation algorithm.

[0008] Document DE 10 2011 076838 A1 discloses a method for creating a diagnostic report for a field device. Measured values ​​and system status messages are displayed, and the accumulated status messages are stored.

[0009] A disadvantage of the previously described methods is that the error messages are only output or displayed immediately, i.e., only at the time the error occurs. It is not possible to trace the occurrence of specific errors or malfunctions with a time delay. In particular, the repeated, short-term occurrence of different error messages during individual, time-limited measurement processes is difficult to trace, even with continuous monitoring of the field device.

[0010] Based on the prior art described above, it is therefore an object of the present invention to provide a method for operating a flow measuring device which ensures particularly high observability and reliability of the measured values ​​determined during individual measuring processes.

[0011] According to a first teaching of the present invention, the above-stated object is achieved by a method mentioned at the outset in that the diagnostic unit generates at least one status message based on the status of the flow measuring device and the status message is transmitted to the storage unit and stored in the memory of the storage unit and that, if several status messages are transmitted, these are stored cumulatively in the memory of the storage unit at least for the duration of the measuring process.

[0012] Fundamentally, the method according to the invention is based on the fact that faulty or error-free states in the determination of individual measured values ​​also affect the reliability of variables derived from these measured values. For example, an incorrect determination of the mass flow rate affects the resulting fluid volume. Preferably, the status message issued by the diagnostic unit, if it corresponds to an error message, also contains information regarding the cause of the error, thus simplifying troubleshooting for the user.

[0013] The status of the measured variable determined by the meter unit preferably corresponds to an aggregation of status messages recorded during the measurement process.

[0014] Cumulative storage of status messages can be achieved, for example, by means of an "or" connection between individual status messages.

[0015] According to the invention, it was recognized that the evaluation of an entire measurement process, or the evaluation of measured values ​​determined during the measurement process, can be achieved by cumulatively storing individual status messages that occur during the measurement process, and by making these status messages available to the user after the measurement process has ended. It is particularly advantageous that the status messages are available even if, for example, the faulty state of the flowmeter no longer persists. Overall, the method according to the invention can provide chronological documentation of the status messages.

[0016] At the same time, the method according to the invention ensures that even briefly occurring status messages, which indicate, for example, a temporary malfunction, do not go unnoticed, but are reported to the user even when the malfunction no longer exists. This allows the user to take measures to rectify the malfunction or prevent a specific status message from occurring again even after the measurement process.

[0017] As a result, the method according to the invention provides a particularly reliable method for determining measured values ​​of individual measuring processes.

[0018] According to a first advantageous embodiment, the memory of the storage unit is erased before the start of a new measurement process. This ensures that status messages that did not occur during this measurement process are not erroneously assigned to the subsequent measurement process. The reliability of the assessment of individual measurement processes can thereby be further increased. It is particularly preferred if at least a second memory is present and the status messages stored in the first memory are transferred to the second memory before they are erased.

[0019] According to an alternative embodiment, the memory of the storage unit is erased after the measurement process is completed. Even then, it is advantageous to have a second memory in which the stored status messages are stored before they are erased from the first memory.

[0020] Furthermore, it is advantageous if the diagnostic unit detects a variety of faulty or error-free states, if the diagnostic unit assigns each state to at least one standardized status category, and if the status category is transmitted as a status message and stored in the memory of the storage unit. Standardized status categories of field devices can be found in particular in the NAMUR Recommendation NE 107. Accordingly, the following device states are distinguished: normal Maintenance required Out of specification Functional check Failure

[0021] The advantage of such an assignment is that the individual states are classified, particularly with regard to their significance. Not every status message requires action to eliminate the fault. In addition to the status categories mentioned above, the application of further categories to assess the measured value or the measurement process is possible. Additional categories such as Initial value Overridden value Underridden value

[0022] The above list of status categories is of course not exhaustive.

[0023] It is also advantageous if the diagnostic unit stores the status and the status category assigned to the status as a status message in the memory of the storage unit. This configuration advantageously takes into account that different information is relevant to different users. For example, one user may only be interested in the information that maintenance is required, while another user may be interested in the specific status for troubleshooting purposes.

[0024] In a further embodiment of the method according to the invention, at least individual states are assigned to more than one status category. This is useful, for example, if a malfunction results in a measured value being outside the specification range and, at the same time, the flowmeter requires maintenance.

[0025] Alternatively, it is also advantageous if each condition is assigned to a specific status category. If a specific status category is communicated to the user after a measurement, determining the cause of the error is particularly easy due to the clear assignment in this configuration.

[0026] According to a further embodiment, a counter value is assigned to the state and / or status category, and both the state and / or status category and the associated counter value are stored in the memory of the storage unit. Such a counter value can, for example, be the current total volume. This has the advantage that after the measurement process has ended, not only is it documented that a status message was or is present, but it can also be traced when this status message occurred. The "when" is not an exact temporal information, but rather the continuously evolving counter reading. This process variant ensures a high level of observability of the state of the field device in the form of a flow meter. The linking with counter values ​​provides special additional information that provides deeper insight into possible causes for the occurrence of the linked states.In particular, the memory of the storage unit stores a chronological order of status messages, or one based on the progressive counter reading. When certain status messages occur, the user can then assess whether the subsequently determined measured values ​​are also affected by the status message and should therefore be discarded or handled differently.

[0027] Furthermore, it is advantageous if the counter unit has a display unit and if the counter unit outputs the status message, particularly together with the counter value, via the display unit at least temporarily. For example, it is advantageous if the counter unit displays the status message, particularly together with the counter value, for the duration of the faulty or error-free state. This allows the user to be informed particularly quickly about any malfunctions or faults. Furthermore, the user can decide early on whether to terminate a faulty measurement process or abort it prematurely.

[0028] According to the invention, the storage unit continuously makes the accumulated status messages available during the time-limited measuring process via an interface, preferably via a display unit or an internal interface.

[0029] For this purpose, the storage unit preferably has a display unit via which the accumulated status messages are output continuously or at at least one point in time during the measurement process, wherein the at least one point in time does not correspond to the end of the measurement process. It is also conceivable that the accumulated status messages can be retrieved or output via an internal interface at any time during a measurement process. Based on the information the user receives from the accumulated status messages during the measurement process, they can decide to abort a measurement process early or to stop the flow without having to continuously monitor the measurement.

[0030] According to a further embodiment of the method, the accumulated status messages that have occurred up to this counter value are assigned to at least one counter value that lies within the measuring process, and the accumulated status messages are continuously made available together with the counter value during the time-limited measuring process via an interface, preferably via a display unit or an internal interface. For this purpose, the memory unit preferably has a display unit via which the accumulated status messages are output together with the counter value continuously or at at least one point in time within the measuring process, wherein the at least one point in time does not correspond to the end of the measuring process. It is also conceivable that the accumulated status messages together with the counter value can be retrieved or output upon request at any time during a measuring process via an internal interface.Based on the information the user receives from the accumulated status messages and the counter value during the measurement process, he or she can decide to abort a measurement process early or to stop the flow of the fluid without having to continuously monitor the measurement.

[0031] According to a further embodiment of the method, the diagnostic unit evaluates the status messages accumulated in the storage unit during the time-limited measurement process and triggers device-specific measures depending on the status messages that occur. For example, the dosing process or the flow of the fluid to be measured can be stopped if at least one previously defined status message occurs.

[0032] In a further development of the method, it is provided that the flow measuring device outputs the status messages accumulated in the storage unit after completion of a measuring process via a data interface of the flow measuring device.

[0033] According to a further development of the method, the diagnostic unit evaluates the status messages accumulated in the storage unit after completion of a time-limited measuring process and only at this point in time, i.e. after completion of the measuring process, triggers or executes device-specific measures, such as shutting down the device, in particular by blocking further measuring processes and / or blocking the flow of the fluid to be measured. This procedure has the advantage that a time-limited measuring process can also be completed once it has begun. This is particularly advantageous if the measuring device operated with the proposed method is used as part of a filling device, such as a dispensing system for propellants or propellant additives.

[0034] According to a second teaching of the present invention, the object mentioned at the outset is also achieved by a flow measuring device with a diagnostic unit for detecting a faulty or fault-free state of the flow measuring device and for generating and forwarding a status message, with a counter unit for determining the total volume of a fluid passing through the flow measuring device during a measuring process and with a storage unit with at least one memory, wherein the status message is stored in the memory of the storage unit and wherein, if several status messages are transmitted, these are stored cumulatively in the memory of the storage unit at least for the duration of the measuring process.

[0035] Particularly preferably, the flow measuring device is designed to carry out one of the previously described methods, i.e., by suitable programming of the diagnostic unit, it is designed in such a way that it actually carries out the previously described method in the operating state, i.e., it cannot theoretically carry out the method only due to its hardware equipment.

[0036] In detail, there are now numerous possibilities for designing and developing the method and flowmeter according to the invention. Reference is made to the claims subordinate to the independent claims as well as to the following description of preferred embodiments in conjunction with the drawings. The drawings show: Fig. 1 shows an embodiment of a method according to the invention and Fig. 2 shows an embodiment of a flow measuring device according to the invention.

[0037] Fig. 1 shows a first embodiment of a method 1 according to the invention for operating a flow measuring device 2, wherein the flow measuring device 2 has at least one diagnostic unit 3, a counter unit 4 and a storage unit 5 with at least one memory 6, wherein the counter unit 4 determines at least the total volume of a fluid passing through the flow measuring device 2 during a measuring process, and wherein the counter unit 4 is operated for the duration of a time-limited measuring process.

[0038] First, in a first step 7, before the start of a time-limited measuring process, the memory 6 of the storage unit 5 is erased. This could, for example, involve the withdrawal of a liquid from a fuel pump.

[0039] In a next step 8, the diagnostic unit 3 detects a faulty or fault-free state of the flow meter 2 and generates 9 a corresponding status message 9a based on the state.

[0040] In a next step 10, the diagnostic unit 3 assigns the state to a status category according to the NAMUR recommendations NE 107. The assignment is made in such a way that each state is assigned to exactly one status category.

[0041] In a subsequent step 11, the diagnostic unit 3 transmits the status information and the status as a status message 9a to the counter unit 4. This assigns a counter value in the form of a current total flow to the status information and the status message 9a 12 and forwards the combination of counter value, status category and status to the storage unit 5 13. At the same time, the counter unit 4 outputs the status category and the status via a display unit 14 15. The storage unit 5 stores 16 the status category and the status together with the counter value.

[0042] After completion of the measurement process 17, a chronological aggregation of the status messages 9a that occurred is available to the user.

[0043] The method 1 according to the invention provides a method 1 for operating a flow measuring device 2, which guarantees a particularly high reliability of the determined measured values ​​in time-limited measuring processes.

[0044] In the method according to the invention, the storage unit 5 has a display unit 14 or an internal interface via which the storage unit 5 continuously outputs the accumulated status messages 9a together with the current total flow during the measuring process.

[0045] Fig. 2shows an embodiment of a flow meter 2 according to the invention with a diagnostic unit 3 for detecting a faulty or fault-free state and for generating and forwarding a status message, with a counter unit 4 for determining the volume passing through the flow meter 2 and with a storage unit 5 with at least one memory 6, wherein the status message 9a is stored in the memory 6 of the storage unit 5 and wherein, if several status messages 9a are transmitted, these are stored cumulatively in the memory 6 of the storage unit 5 at least for the duration of the measuring process. The flow meter 2 shown is designed to carry out a method according to the invention. In addition, the counter unit 4 has a display unit 14 via which the counter unit 4 outputs the status message 9a.

[0046] In detail, the flow meter 2 is designed such that the status message 9a can be transmitted from the diagnostic unit 3 either directly to the storage unit 5 or indirectly via the counter unit 4 to the storage unit 5. All components 3, 4, and 5 are designed such that they can act as transmitters or receivers.

[0047] In a next embodiment, the storage unit also has a display unit 14 or an internal interface, via which the storage unit 5 continuously outputs the accumulated status messages 9a together with the current total flow during the measuring process. Reference symbol

[0048] 1Method for operating a flowmeter 2Flowmeter 3Diagnostic unit 4Counter unit 5Storage unit 6Memory 7Deleting the memory of the storage unit 8Detection of a faulty or fault-free state 9Generation of a status message 9aStatus message 10Assignment of the state to a status category 11Transmission to the counter unit 12Assignment to a counter value 13Forwarding to the storage unit 14Display unit 15Output of the status category and the state via a display unit 16Saving the status category and the state 17Ending the measurement process

Claims

1. Method (1) for operating a flowmeter (2) for performing a plurality of time-limited measuring operations, wherein the flowmeter (2) has at least one diagnostic unit (3), a counter unit (4) and a memory unit (5) with at least one memory (6), wherein the counter unit (4) determines at least the total volume of a fluid passing through the flowmeter (2) during a measuring operation, so that by means of the specification of the total volume, each point in time of the measuring process can be determined precisely and a chronological mapping to the measuring process is possible on the basis of the total volume, and wherein the counter unit (4) is operated for the duration of a time-limited measuring process, comprising the following method steps: determining (8) at least one faulty or fault-free state of the flowmeter (2) by the diagnostic unit (3), wherein the diagnostic unit (3) generates (9) at least one status message (9a) based on the state, and wherein the status message (9a) is transmitted to the memory unit (5) and stored in the memory (6) of the memory unit (5), wherein, if several status messages (9a) are transmitted, these are stored cumulatively in the memory (6) of the memory unit (5) at least for the duration of the measuring process, characterized in that the memory unit (5) continuously makes the accumulated status messages (9a) available via an interface during a time-limited measuring process.

2. Method (1) according to claim 1, characterized in that the memory (6) of the memory unit (5) is deleted (7) before the start of a new measurement process.

3. Method (1) according to claim 1 or 2, characterized in that the diagnostic unit (3) detects a plurality of faulty or fault-free states, that the diagnostic unit (3) assigns each state to at least one standardized status category and that the status category is transmitted as a status message (9a) and stored in the memory (6) of the memory unit (5).

4. Method (1) according to claim 3, characterized in that the diagnostic unit (3) stores the status and the status category assigned to the status as a status message (9a) in the memory (6) of the memory unit (5).

5. Method (1) according to any one of claims 1 to 4, characterized in that a counter value is assigned to the state and / or the status category and both the state and / or the status category and the associated counter value are stored in the memory (6) of the memory unit (5).

6. Method (1) according to any one of claims 1 to 5, characterized in that the counter unit (4) has a display unit (14), and that the counter unit (4) issues the status message (9a) via the display unit (14).

7. Method (1) according to any one of claims 1 to 6, characterized in that the memory unit (5) continuously makes the accumulated status messages (9a) available during a time-limited measuring process via a display unit (14) or an internal interface.

8. Method (1) according to any one of claims 5 to 7, characterized in that the accumulated status messages (9a) which have occurred up to this counter value are assigned to at least one counter value which lies within the time-limited measurement process, and that the accumulated status messages (9a) are continuously made available together with the counter value during the time-limited measurement process via an interface, preferably via a display unit (14) or an internal interface.

9. Method according to any one of claims 1 to 8, characterized in that the diagnostic unit (3) evaluates the status messages (9a) accumulated in the memory unit during the time-limited measuring process and triggers device-specific measures in dependence on the status messages (9a) that have occurred, in particular stops the flow of the fluid to be measured when at least one previously defined status message occurs.

10. Method (1) according to any one of claims 1 to 8, characterized in that the diagnostic unit (3) evaluates the status messages (9a) accumulated in the memory unit (5) after completion of a time-limited measuring process and only triggers device-specific measures at this point in time, i.e. after completion of the measuring process, in particular blocks further measuring processes and / or blocks the flow of the fluid to be measured.

11. Flowmeter (2) with a diagnostic unit (3) for detecting a faulty or fault-free state and for generating and forwarding a status message (9a), with a counter unit (4) for determining the total volume of a fluid passing through the flowmeter (3) during a measuring operation, so that by means of the specification of the total volume, each time of the measuring process can be determined precisely and a chronological mapping of the measuring process is possible on the basis of the total volume, and with a memory unit (5) with at least one memory (6), wherein the status message (9a) is stored in the memory (6) of the memory unit (5) and wherein, if a plurality of status messages (9a) are transmitted, these are stored cumulatively in the memory (6) of the memory unit (5) at least for the duration of the measuring process, characterized in that the memory unit (5) continuously makes the accumulated status messages (9a) available via an interface during a time-limited measuring process.

12. Flowmeter (2) according to claim 11, characterized in that the flowmeter (2) is designed to carry out a method (1) according to any one of claims 1 to 10.