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 least two different temperature values, and/or 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 considering the ascertained temperature dependence and/or the ascertained voltage dependence.

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: A method for determining and/or monitoring a process variable of a medium, wherein a mechanically oscillatable unit is supplied with an exciter signal wherein a received signal coming from the mechanically oscillatable unit is received, and wherein the exciter signal is produced in such a manner, that a phase difference between the exciter signal and the received signal equals a predeterminable phase value. A criterion for judging the determining of the phase difference between the exciter signal and the received signal, or a signal dependent on the exciter signal or on the received signal, is established; in the case, in which the criterion for judging the determining of the phase difference is fulfilled, tuning of the phase difference is closed-loop controlled; and, in the alternative case, tuning of the phase difference is open-loop controlled. An apparatus associated with the method is also disclosed.

Abstract: An apparatus including: a mechanically oscillatable unit; an exciting/receiving unit; and an electronics unit having an input amplifier and an output amplifier. The amplification factors of the output amplifier and the input amplifier are tunable. The control unit tunes the amplification factor of the output amplifier as a function of damping of the mechanically oscillatable unit in such a manner that the amplitude of the electrical, input signal lies within an amplitude band and that the amplification factor of the output amplifier decreases in the case of lessened damping by the medium and increases in the case of greater damping by the medium, and the control unit tunes the amplification factor of the output amplifier and the amplification factor of the input amplifier in such a manner that the total amplification factor of the electronics unit equals a predeterminable value.

Abstract: Method for determining and/or monitoring a process variable of a medium, wherein a mechanically oscillatable unit is supplied with an exciter signal wherein a received signal coming from the mechanically oscillatable unit is received, and wherein the exciter signal is produced in such a manner, that a phase difference between the exciter signal and the received signal equals a predeterminable phase value. A criterion for judging the determining of the phase difference between the exciter signal and the received signal, or a signal dependent on the exciter signal or on the received signal, is established; in the case, in which the criterion for judging the determining of the phase difference is fulfilled, tuning of the phase difference is closed-loop controlled; and, in the alternative case, tuning of the phase difference is open-loop controlled. An apparatus associated with the method is also disclosed.

Abstract: An apparatus including: a mechanically oscillatable unit; an exciting/receiving unit; and an electronics unit having an input amplifier and an output amplifier. The amplification factors of the output amplifier and the input amplifier are tunable. The control unit tunes the amplification factor of the output amplifier as a function of damping of the mechanically oscillatable unit in such a manner that the amplitude of the electrical, input signal lies within an amplitude band and that the amplification factor of the output amplifier decreases in the case of lessened damping by the medium and increases in the case of greater damping by the medium, and the control unit tunes the amplification factor of the output amplifier and the amplification factor of the input amplifier in such a manner that the total amplification factor of the electronics unit equals a predeterminable value.