Method for monitoring power consumption of measurement point, and measurement point and process control system

Abstract

The invention relates to a method for monitoring power consumption of a measurement point, as well as a measurement point and a process control system. A method for monitoring the power consumption of a measurement point having a two-wire structure, comprising the following steps: providing a measurement point having a measurement transducer and a sensor, the measurement transducer having a loop input and a loop output, which are connected via a current loop to a control center for power and data transmission, wherein the measuring transducer is connected to the sensor for energy and data transmission,-a sensor measurement value is determined by the sensor,-a transmission current dependent on the sensor measurement value is output by the measuring transducer at the loop output,-a supply voltage provided between the loop input and the loop output of the measuring transducer is determined by the control center, -determining a supply power on the basis of the supply voltage and the transmission current,-determining a power consumption of the measurement transducer,-comparing the power consumption with the supply power,-outputting user information dependent on the comparison.

Description

Technical Field

[0001] The invention relates to a method for monitoring the power consumption of a measuring point, as well as a measuring point and a process control system. Background Art

[0002] In analytical measurement technology, especially in the field of water management, environmental analysis, in industry, for example in food technology, biotechnology and medicine, and for the most varied laboratory applications, measured variables such as pH, conductivity or even concentration of analytes, such as ions or dissolved gases in a gaseous or liquid measurement medium, are of great importance. These measured variables can be acquired and / or monitored, for example, by means of electrochemical sensors such as optical sensors, potentiometric sensors, amperometric sensors, voltammetric sensors or coulometric sensors, or also conductivity sensors.

[0003] The sensor measured values ​​determined by the sensor are processed in the so-called measuring transducer. The challenge that arises here, especially in potentially explosive environments, is that only a limited level of energy can be supplied to the measuring transducer. It is in potentially explosive areas that so-called two-wire field devices are usually used. Historically, such two-wire field devices have been mainly designed so that the current intensity between 4mA and 20mA (= milliamperes) of the supply current flowing in the single wire pair designed as a current loop also represents the measured value currently generated by the field device or measuring point, or the set value currently transmitted to the field device. As a result, a specific problem of such two-wire field devices is that the electrical power that can be converted or to be converted by the field device electronics, hereinafter referred to as "available power", at least nominally, can fluctuate within a wide range during operation. With this in mind, modern two-wire field devices (2L field devices), especially modern two-wire measuring devices (2L measuring devices) with a (4mA to 20mA) current loop, are therefore usually designed so that their device functions - implemented by means of a microcomputer provided in the evaluation and operating circuit - are limited to this, which may be performed at the minimum current value. Some devices also operate so that energy-intensive operations of the microcontroller are repeatedly interrupted until an energy storage (e.g., a capacitor) coupled thereto is sufficiently filled to continue operation. Summary of the invention

[0004] It is therefore an object of the present invention to propose a method which facilitates the operation of a field device with fluctuating available power.

[0005] This object is achieved according to the invention by a method for monitoring the power consumption of a measuring point with a two-wire structure according to claim 1 .

[0006] The method according to the invention comprises the following steps:

[0007] - providing a measuring point with a measuring transducer and a sensor, wherein the measuring transducer has a loop input and a loop output, which are connected to a control center via a current loop for power and data transmission, wherein the measuring transducer is connected to the sensor for energy and data transmission,

[0008] - a sensor measurement value is determined by the sensor,

[0009] - the output of a transmission current at the loop output by the measuring transducer which depends on the sensor measurement value,

[0010] - the supply voltage provided between the loop input and the loop output of the measuring transducer is determined by the control center,

[0011] - determining the supplied power based on the supplied voltage and the transmitted current,

[0012] - determine the power consumption of the measuring transducer,

[0013] - compare power consumption with power supplied,

[0014] - Outputs user information that depends on the comparison.

[0015] The method according to the invention enables the power consumption of a measuring point to be monitored and made available to the user. This makes it possible to perform energy-consuming activities at the optimal time without compromising the usual measuring operation of the measuring point. In addition, the user can see at a glance the currently available supply power or power consumption.

[0016] According to one embodiment of the invention, via the output unit, the user information is output at the control center after being transmitted to the control center, and / or the user information is output at the measuring transducer.

[0017] According to a further embodiment of the invention, in the comparison it is checked whether the supplied power is sufficient for an additional activity of the measuring transducer, wherein the user information contains a result of the check.

[0018] According to one embodiment of the present invention, in the step of outputting the transmission current according to the sensor measurement value, a mathematical map is used to determine the transmission current to be output, wherein if the supplied power is insufficient for the additional activity, the user information will include a suggestion for power optimization, wherein the power optimization includes an adjustment of the mathematical map so that a higher transmission current is output for the sensor measurement value than before the adjustment of the mathematical map. If the maximum transmission current is allowed If the current limit is 20 mA, for example in explosion-proof areas, this upper current limit must of course be taken into account in the adjustment.

[0019] According to one embodiment of the invention, the method further performs the steps of data processing in the measuring transducer and / or wireless communication via the communication module if the power supply is sufficient for the additional activity.

[0020] According to one embodiment of the invention, the development of the residual power over time based on the comparison is stored and analyzed in the measuring transducer.

[0021] According to one embodiment of the invention, the user information indicates a power / time window in which the remaining power is sufficient for certain operations of the measurement transducer when the remaining power based on the analysis cycles over time.

[0022] According to one embodiment of the invention, the result of the analysis of the development of the residual power over time is used to determine a point in time for the automatic initiation of certain operations of the measuring transducer.

[0023] The above-mentioned object is also achieved by a measuring point according to claim 9 .

[0024] The measuring points according to the present invention include:

[0025] a measuring transducer having a loop input and a loop output, wherein the loop input and the loop output are suitable for connection to a control center via a current loop for power and data transmission,

[0026] - sensors connected to measuring transducers for power and data transmission,

[0027] The measuring points are suitable for carrying out the method according to the invention.

[0028] The above object is also achieved by a process control system according to claim 10 .

[0029] The process control system according to the present invention comprises:

[0030] - a measuring point according to the invention,

[0031] A control center which is connected to the measuring points for energy and data transmission, wherein the measuring transducers and / or the control center have a display unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The invention is explained in more detail based on the following description of the accompanying drawings. In the accompanying drawings:

[0033] - Figure 1 A schematic representation of a process control system according to the present invention is shown. DETAILED DESCRIPTION

[0034] Figure 1The process control system 100 according to the invention shown comprises a measuring point 1 and a control center 30. The measuring point 1 is connected to the control center 30 for energy and data transmission. The measuring point 1 and / or the control center 30 has a display unit 40. The output unit 40 is, for example, a display or other user interface. The control center 30 has a DC voltage source, which is characterized in that Figure 1 U IN The voltage of the DC voltage source may preferably be regulated.

[0035] The measuring point 1 comprises a measuring transducer 10 and a sensor 20 or a device combining the two functions. The measuring transducer 10 has a loop input 11 and a loop output 12, wherein the loop input 11 and the loop output 12 are suitable for connecting to a control center 30 via a current loop 13 for power and data transmission. The sensor 20 is connected to the measuring transducer 10 for power and data transmission. The measuring point 1 is a field device or a combination of field devices, wherein energy and data are transmitted via the same interface. Preferably, the measuring transducer 10 or the measuring point 1 is a two-wire field device.

[0036] The method according to the invention for monitoring the power consumption of a measuring point 1 is discussed below.

[0037] The first step consists in providing the above-mentioned measuring point 1. The measuring transducer 10 is connected to the control center 30 for power and data transmission via a current loop 13. The current loop 13 preferably allows a current of 4 mA to 20 mA to flow.

[0038] In the next step, the sensor measurement value MW is determined by the sensor 20. Figure 1 In the example, the sensor measurement value MW is also represented as x MEAS Depending on the type of sensor 20 , the sensor measurement value MW is, for example, a voltage (for example, at a pH sensor) or a resistance value (for example, at a temperature sensor). The measuring transducer 10 processes the sensor measurement value MW so that the sensor measurement value MW is converted into a transmission current. . Transmission current Between 4mA and 20mA. Transmission current Directly depends on the sensor measured value MW. Transmission current Preferably proportional to the sensor measurement value MW. Current transmission current , transmission current The development over time and / or the current sensor measurement value MW, or the development over time of the sensor measurement value MW, is preferably stored in a memory of the measuring transducer 10 .

[0039] Next, the measuring transducer 10 outputs the transmission current at the loop output 12. steps. Since the transmission current Dependence on the sensor measurement value MW, the transmission current is directly The sensor measurement value MW is formed. This allows the control center 30 to receive the transmission current Direct inference of the sensor measurement value MW. Transmission current Preferably not more than 20 mA is used in order to also be used in potentially explosive atmospheres.

[0040] In a further step, a supply voltage VS is determined which is provided by the control center 30 between the loop input 11 and the loop output 12 of the measuring transducer 10. The supply voltage VS is preferably equal to the supply voltage provided by the DC voltage source U IN However, in an embodiment (not shown), the current loop 13 has an additional load, so that the power supply voltage VS is lower than that provided by the DC voltage source U In The measuring transducer 10 preferably stores the current supply voltage VS and its development over time in a memory.

[0041] Next, a voltage based on the supply voltage VS and the transmission current Step of determining the supply power VL. For this purpose, the measuring transducer 10 multiplies the current supply voltage VS by the current delivery current The current supply power VL and the development of the supply power VL over time are preferably stored by the measuring transducer 10 .

[0042] In a next step, the power consumption BL of the measuring transducer 10 is determined. The power consumption BL is the electrical power required by the measuring transducer 10. This includes, for example, the electrical energy required for the operation of the sensor 20 or the electrical power required by the measuring transducer 10 to operate internal control modules such as a microprocessor or output units 40 such as status LEDs, a display, a loudspeaker, data communication of the communication module 14, etc. The communication module 14 is suitable for communicating with a communication station 50.

[0043] Then a step of comparing the power consumption BL with the supplied power VL is performed. In this case, it is preferred to determine the remaining power , which is the difference between the supplied power VL and the power consumption BL. Since the supplied power VL depends directly on the transmission current The current in turn depends on the sensor measurement value MW, so that under certain measurement conditions it may happen that the sensor 20 measures only a small sensor measurement value MW. proportional mapping, which therefore results in a low transfer current And thus leads to low supply power VL. In this case, the remaining power Only low, its Figure 1 Zhongyou In the opposite case, i.e. when the sensor measured value MW is high and therefore the transmission current is high and high supply power VL exists, the remaining power will also be high, which is Figure 1 Zhongyou instruct. Figure 1 Also shows the remaining power The curve of the residual power The curve thus indirectly shows the development of the supplied power VL and the power consumption BL over time. Of course, in addition to the remaining power In addition, the supplied power VL and the power consumption BL or their development over time can also be displayed.

[0044] According to one embodiment, in the comparison it is checked whether the supplied power VL is sufficient for an additional activity of the measuring transducer 10. For this purpose, for each additional activity the wagered power requirement is stored in the measuring transducer 10. This means that the measuring transducer 10 knows the additional power consumption of, for example, the communication module 14.

[0045] Furthermore, there is a step of outputting user information BI which is dependent on the comparison. The user information BI is output at the measuring transducer 10 by means of the output unit 40 and / or at the control center 30 after the user information BI has been sent to the control center 30. Figure 1 As shown, the current residual power , , For example, it is output on a display of the measuring transducer 10. Of course, the current power consumption BL and / or the current supplied power VL can also be output separately or simultaneously. For example, a tachometer display is used to output (see Figure 1 Of course, it is also possible to use, for example, a diagram (see Figure 1 ) Output the remaining power and / or the development of the supplied power VL and / or the power consumption BL over time. Preferably, in addition to the representation of the user information BI, for example a signal color is used, which allows the user to more quickly recognize whether the supplied power VL is sufficient (signal color is green), critical (signal color is orange), or too low (signal color is red) in order to start or delay energy-consuming activities such as wireless data transmission performed by the communication module 14 in the measuring transducer 10.

[0046] When the above check is performed, the result of the check is preferably output together with the user information BI. In particular, if the user desires data transmission through the communication module 14, but the supply power VL is insufficient, an error message or a warning with / without recommendation is output together with the user information BI.

[0047] Preferably, the output is dependent on the transmission current of the sensor measurement value MW In the step of determining the transmission current to be output, In this case, if the supplied power VL is not sufficient for the additional activity, the user information BI will include a suggestion for power optimization. The power optimization includes an adjustment of the mathematical mapping such that a higher transmission current US is output for the sensor measurement value MW than before the adjustment of the mathematical mapping.

[0048] If the supplied power VL is sufficient for the additional activity, the method will further perform the steps of data processing in the measuring transducer 10 and / or wireless communication via the communication module 14 .

[0049] According to one embodiment of the method, the residual power in the measuring transducer 10 is stored and analyzed. In particular, it is checked whether there is a residual power If there is such a residual power As time goes by, the power time window ZF will be output together with the user information BI, where the remaining power High enough to perform some operations (see Figure 1 ). Therefore, in this power time window ZF, additional activities or operations of the measuring transducer 10 can be performed well. "Cyclic" is here to be understood to mean that the residual power is estimated. For example, the assessment of residual power through "artificial intelligence" of the remaining power and estimate future developments. Recognize patterns during development.

[0050] Remaining power The analysis results of the development over time, i.e. in particular the identified power time windows ZF, are preferably used to determine the point in time for the automatic start of certain activities or operations of the measuring transducer 10. In particular, the exchange of larger amounts of data, firmware updates, for example via the communication module 14 and the communication station 50, can be conveniently and securely transmitted.

[0051] List of reference numerals

[0052] 1 measuring point

[0053] 10 Measurement transducer

[0054] 11 loop input

[0055] 12 loop output

[0056] 13 Current loop

[0057] 14 Communication module

[0058] 20 sensors

[0059] 30Control Center

[0060] 40 output units

[0061] 50 communication stations

[0062] 100Process Control Systems

[0063] MW sensor measurement value

[0064] Transmission current

[0065] , , Remaining power

[0066] VS Supply Voltage

[0067] VL supply power

[0068] BL Power Consumption

[0069] BI User Information

[0070] ZF Power Time Window

Claims

1. A method for monitoring the power consumption of a measuring point (1) having a two-wire structure, comprising the following steps: - providing a measuring point (1) with a measuring transducer (10) and a sensor (20), wherein the measuring transducer (10) has a loop input (11) and a loop output (12), wherein the loop input (11) and the loop output (12) are connected to a control center (30) via a current loop (13) for power and data transmission, wherein the measuring transducer (10) is connected to the sensor (20) for energy and data transmission, - determining a sensor measurement value (MW) by means of said sensor (20), - the measuring transducer (10) outputs a transmission current (MW) at the loop output (12) which is dependent on the sensor measurement value (MW) ), - determining, by the control center (30), a supply voltage (VS) provided between the loop input (11) and the loop output (12) of the measuring transducer (10), - Based on the supply voltage (VS) and the transmission current ( ) determines the supply power (VL), - determining the power consumption (BL) of the measuring transducer (10), - comparing the power consumption (BL) with the supplied power (VL), - Output user information (BI) depending on the comparison.

2. The method according to claim 1, wherein: Via an output unit (40), after the user information (BI) has been transmitted to the control center (30), the user information (BI) is output at the control center (30) and / or the user information (BI) is output at the measuring transducer (10).

3. A method according to any one of the preceding claims, wherein: In the comparison, it is checked whether the supplied power (VL) is sufficient for an additional activity of the measuring transducer (10), wherein the user information (BI) contains the result of the test.

4. The method according to claim 3, wherein: The output depends on the sensor measurement value (MW) of the transmission current ( ) step, using the transmission current to be output ( ), wherein, if the supplied power (VL) is insufficient for the additional activity, the user information (BI) will include a suggestion for power optimization, wherein the power optimization includes an adjustment of the mathematical mapping such that a higher transmission current (US) is output for the sensor measurement value (MW) than before the adjustment of the mathematical mapping.

5. The method according to claim 3, wherein: If the supplied power (VL) is sufficient for additional activities, the method will further carry out the steps of data processing in the measuring transducer (10) and / or wireless communication via a communication module (14).

6. A method according to any one of the preceding claims, wherein: The residual power ( ) develop over time.

7. The method according to claim 6, wherein: The user information (BI) indicates a power time window (ZF), in which the remaining power ( ) cycles over time, the remaining power ( ) is sufficient for certain operations of the measuring transducer (10).

8. The method according to claim 6 or claim 7, wherein: The remaining power ( ) The result of the analysis of the development over time is used to determine a point in time for the automatic start of certain operations of the measuring transducer (10).

9. A measuring point (1), comprising: a measuring transducer (10) having a loop input (11) and a loop output (12), wherein the loop input (11) and the loop output (12) are suitable for connection to a control center (30) via a current loop (13) for power and data transmission, - a sensor (20) connected to the measuring transducer (10) for power and data transmission, Therein, the control unit (1) is adapted to perform the method according to any of the preceding claims.

10. A process control system (100), comprising: - a measuring point (1) according to claim 9, A control center (30) which is connected to the measuring point (1) for energy and data transmission, wherein the measuring transducer (10) and / or the control center (30) has a display unit (40).

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