Abstract: The invention relates to a signal generator for producing periodic signals for a measuring apparatus (1) of automation technology, wherein the signals have sequential, discrete signal frequencies, which lie within a predetermined frequency range, a control- and/or computing unit (4), a clock signal producer (6), wherein the clock signal producer (6) provides a constant sampling frequency, which is greater than the maximum discrete signal frequency in the predetermined frequency range, a memory unit (7), in which for each of the discrete signal frequencies the amplitude values of the corresponding periodic signals are stored or storable as a function of the sampling frequency, wherein the control- and/or computing unit (4) reads out the stored or storable amplitude values of the discrete frequencies successively with the sampling frequency of the clock (6) from the memory unit (7) and produces the periodic signals or forwards for producing, and a static filter unit (12) with a limit frequency, which lies above

Abstract: A method and an apparatus for monitoring at least one media-specific property of a medium in automation technology with a measuring probe, wherein the at least one media-specific property is ascertained in a conductive operating mode and in a capacitive operating mode of the measuring probe. The conductive operating mode and the capacitive operating mode are operated alternately, wherein based on the measured values, which are ascertained in at least one of the two operating modes, it is checked, whether the at least one media-specific property to be monitored lies within a predetermined tolerance band, and wherein a report and/or a switching signal is generated, when the at least one media-specific property to be monitored lies outside of the predetermined tolerance band.

Abstract: A method and an apparatus for monitoring a set fill level of a medium in a container using a fill level measuring probe that is designed to operate as a conductive fill level measuring probe in a conductive operating mode and as a capacitive fill level measuring probe in a capacitive operating mode, with a control/evaluation/output unit that is designed to alternately trigger conductive operating mode and capacitive operating mode, and with a control/evaluation/output unit that determines whether the set fill level of the medium in the container has been reached on the basis of the measured values from the two operating modes, and which generates a message when the set fill level is exceeded and/or undershot.

Abstract: A method for stabilizing the clock frequency of a microcontroller associated with a field device of automation technology. The field device as a function of application is exposed to different process conditions, wherein the clock frequency of the microcontroller is ascertained at at least two different temperature values, and/or at at least two different voltage values. Based on the ascertained values, the dependence of the clock frequency of the microcontroller on temperature over a predetermined temperature- and/or frequency range and/or the dependence of the clock frequency of the microcontroller on voltage over a predetermined voltage- and/or frequency range is ascertained. The ascertained values are stored, and the influence of temperature and/or voltage on the clock frequency of the microcontroller is at least approximately compensated taking into considerating the ascertained temperature dependence and/or the ascertained voltage dependence.

Abstract: An apparatus for synchronizing the clock frequencies of a first electronics unit arranged on the primary side, and a second electronics unit arranged on the secondary side. Associated with the first electronics unit is a clock signal producer, which produces a clock signal having a reference clock frequency, wherein a transmission unit is provided between the first electronics unit and the second electronics unit. A first control unit is provided, which operates the transmission unit with a clock frequency, which amounts to a fraction of the reference clock frequency of the first electronics unit, wherein a second control unit is provided, which couples the clock frequency out to the secondary side and, based on the out-coupled clock frequency, produces for the second electronics unit a clock frequency, which is synchronous with the reference clock frequency of the first electronics unit.

Abstract: An apparatus for determining and/or monitoring a process variable of a medium in a container. including: a probe unit, which has a sensor electrode and a guard electrode; and an electronics unit, which supplies the sensor electrode with an activating signal and which supplies the guard electrode with a guard signal; An amplifying unit; and a limiting element arranged in series between the guard electrode and the output of the amplifying unit. The amplifying unit supplies via the limiting element the guard electrode with the guard signal; and the amplifying unit supplies via the limiting element the sensor electrode with the activating signal. The evaluating unit is provided, which determines and/or monitors the process variable based on an electrical current signal measurable at the sensor electrode, and the activating signal and/or the guard signal.

Abstract: The invention relates to an apparatus for capacitive determining and/or monitoring at least of fill level of a medium in a container, comprising a probe unit having at least one probe electrode, and an electronics unit, which supplies at least the probe electrode with an electrical, transmitted signal, and receives and evaluates an electrical, response signal from the probe unit. Besides relating to an apparatus, the invention also relates to a corresponding method. The invention is distinguished by features including that an electronics unit supplies the probe electrode at least at times by means of a frequency sweep with a transmitted signal, which has a plurality of discrete frequencies following one another within a predeterminable frequency band, that the electronics unit, based on the frequency sweep, ascertains a measuring frequency optimal for present application parameters, and that the electronics unit determines fill level from the response signal belonging to the optimal measuring frequency.

Abstract: A measuring device for determining and/or monitoring at least one process variable, comprising: a sensor unit; a first electronics unit which has a first microcontroller, and a second electronics unit which has a second microcontroller, and which is connected with the first electronics unit via a galvanically isolated transmission unit for energy- and data transmission. The first microcontroller produces at least one signal, which can vary in at least one characteristic, and supplies the signal to the transmission unit, that the signal controls the energy- and data transmission, that the first microcontroller and/or the second microcontroller determines at least one current operating parameter, and that the first microcontroller sets at least one characteristic of the signal as a function of the operating parameter.

Abstract: An apparatus for determining and/or monitoring at least one process variable of a medium. The apparatus includes: at least one sensor unit for registering the process variable, wherein the sensor unit produces measurement signals; at least one electronics unit for controlling the sensor unit, wherein the electronics unit has at least one microprocessor; and at least one memory unit, which is associated with the sensor unit, and in which control data are storable. The control data specifically relate to the sensor unit and can be read out by the electronics unit. The microprocessor of the electronics unit is embodied in such a manner, that the microprocessor executes in an inactive state only basic functionalities, and that the microprocessor in an active state controls the sensor unit. The microprocessor transfers from the inactive state into the active state transfers by loading control data from the memory unit.

Abstract: An apparatus for ascertaining and/or monitoring a process variable. The apparatus includes a sensor element, and at least one electronics unit, which, for measuring the process variable, supplies the sensor element with an electrical exciter signal, receives an electrical measurement signal from the sensor element and evaluates the measurement signal with respect to the process variable. An analog-digital converter is provided in the electronics unit. For measuring the process variable, the electronics unit supplies the sensor element with a first exciter signal and a second exciter signal, timewise one after the other, in such a manner, that the first exciter signal and the second exciter signal have a settable phase (?)relative to one another.

Abstract: An apparatus for capacitive ascertaining and/or monitoring of the fill level of a medium in a container. The apparatus includes at least one probe unit, which is electrically insulated relative to the medium, and at least one electronics unit, which supplies the probe unit with at least one electrical, actuating signal, receives an electrical measurement signal from the probe unit, and evaluates the measurement signal as regards the fill level The actuating signal is an electrical alternating voltage signal. The electronics unit is embodied in such a manner that it supplies the probe unit with the actuating signal in a measuring phase, and supplies the probe unit with a test signal in a test phase, and that it receives a test measurement signal in the test phase from the probe unit, wherein the test signal is selected in such a manner that it has at least one section with an essentially constant voltage value.

Abstract: A method for manufacturing-side calibration of a measuring device for capacitive fill level measurement of a medium, wherein at least one probe unit of the measuring device is activated with an electrical, alternating voltage of a predeterminable frequency. As a function of the frequency of the activating signal, a conductivity range is determined, within which the fill level measurement is essentially independent of a change of the electrical conductivity of the medium; for such conductivity range, at least a first reference matching between a predeterminable, first fill-level value and a first capacitance value belonging to the first fill-level value is produced; and the first reference matching between the first fill-level value and the first capacitance value is recorded. Additionally, the invention relates to a corresponding measuring device.

Abstract: An apparatus for determining and/or monitoring a process variable of a medium in a container. including: a probe unit, which has a sensor electrode and a guard electrode; and an electronics unit, which supplies the sensor electrode with an activating signal and which supplies the guard electrode with a guard signal; An amplifying unit; and a limiting element arranged in series between the guard electrode and the output of the amplifying unit. The amplifying unit supplies via the limiting element the guard electrode with the guard signal; and the amplifying unit supplies via the limiting element the sensor electrode with the activating signal. The evaluating unit is provided, which determines and/or monitors the process variable based on an electrical current signal measurable at the sensor electrode, and the activating signal and/or the guard signal.

Abstract: An apparatus for determining and/or monitoring at least one process variable of a medium. The apparatus includes: at least one sensor unit for registering the process variable, wherein the sensor unit produces measurement signals; at least one electronics unit for controlling the sensor unit, wherein the electronics unit has at least one microprocessor; and at least one memory unit, which is associated with the sensor unit, and in which control data are storable. The control data specifically relate to the sensor unit and can be read out by the electronics unit. The microprocessor of the electronics unit is embodied in such a manner, that the microprocessor executes in an inactive state only basic functionalities, and that the microprocessor in an active state controls the sensor unit. The microprocessor transfers from the inactive state into the active state transfers by loading control data from the memory unit.

Abstract: The invention relates to an apparatus for ascertaining and/or monitoring a process variable. The apparatus includes a sensor element (1), and at least one electronics unit (2), which, for measuring the process variable, supplies the sensor element (1) with an electrical exciter signal (ES1, ES2), receives an electrical measurement signal (MS1, MS2) from the sensor element (1) and evaluates the measurement signal (MS1, MS2) with respect to the process variable. An analog-digital converter (3) is provided in the electronics unit (2). The invention includes that, for measuring the process variable, the electronics unit (2) supplies the sensor element (1) with a first exciter signal (ES1) and a second exciter signal (ES2), timewise one after the other, in such a manner, that the first exciter signal (ES1) and the second exciter signal (ES2) have a settable phase (?) relative to one another.

Abstract: An apparatus for capacitive ascertaining and/or monitoring of the fill level of a medium in a container. The apparatus includes at least one probe unit, which is electrically insulated relative to the medium, and at least one electronics unit, which supplies the probe unit with at least one electrical, actuating signal, receives an electrical measurement signal from the probe unit, and evaluates the measurement signal as regards the fill level The actuating signal is an electrical alternating voltage signal. The electronics unit is embodied in such a manner that it supplies the probe unit with the actuating signal in a measuring phase, and supplies the probe unit with a test signal in a test phase, and that it receives a test measurement signal in the test phase from the probe unit, wherein the test signal is selected in such a manner that it has at least one section with an essentially constant voltage value.

Abstract: A method for manufacturing-side calibration of a measuring device for capacitive fill level measurement of a medium, wherein at least one probe unit of the measuring device is activated with an electrical, alternating voltage of a predeterminable frequency. As a function of the frequency of the activating signal, a conductivity range is determined, within which the fill level measurement is essentially independent of a change of the electrical conductivity of the medium; for such conductivity range, at least a first reference matching between a predeterminable, first fill-level value and a first capacitance value belonging to the first fill-level value is produced; and the first reference matching between the first fill-level value and the first capacitance value is recorded. Additionally, the invention relates to a corresponding measuring device.