Abstract: A field device having a safe interface is based on two voltage regulators designed to set electrical current between corresponding contacts of the interface. The field device tests via which of the contacts the field device is connected with a superordinate unit and an automatic configuration of the interface can be performed for the appropriate transmission standard. Because the contacting to the superordinated unit is checked repetitively by means of two electrical current regulators it is assured that the field device can determine and automatically react to a change of the contacting at the interface even during measurement operation. This makes the interface safe and thereby increases the safety of the process plant, in which the field device is applied.

Abstract: A field device having a safe interface is based on two voltage regulators designed to set electrical current between corresponding contacts of the interface. The field device tests via which of the contacts the field device is connected with a superordinate unit and an automatic configuration of the interface can be performed for the appropriate transmission standard. Because the contacting to the superordinated unit is checked repetitively by means of two electrical current regulators it is assured that the field device can determine and automatically react to a change of the contacting at the interface even during measurement operation. This makes the interface safe and thereby increases the safety of the process plant, in which the field device is applied.

Abstract: An automation field device comprises at least four connection pins for connecting the field device; a field device electronics adapted, in a first operating state, to provide a 4-20 mA signal via a first and second connection pin , in a second operating state, to be supplied with a supply voltage via the first and a third connection pin and via a fourth connection pin to enable an IO-Link communication or to provide a first switch output and supplementally to provide a second switch output on the second connection pin, and, in a third operating state, to be supplied with the supply voltage via the first and third connection pins and via the fourth connection pin to enable the IO-Link communication or to provide the first switch output and supplementally to provide a 4-20 mA current output on the second connection pin.

Abstract: Control electronics for a two-wire process device, which two-wire process device can be connected to a two-wire loop. The control electronics comprises an input circuit and a control unit connected to the input circuit, wherein the input circuit is used in a first operating mode to set a current and/or voltage in the two-wire loop by means of a control signal transmitted by the control unit. The input circuit is used in a second operating mode to automatically, in particular independently of the control unit or independently of the control signal transmitted by the control unit, to set the current and/or the electric voltage in the two-wire loop.

Abstract: A thermo wire testing circuit, comprising: a current source terminal for supplying a test current to a first thermo wire via a first terminal during a test mode; a current drain terminal for receiving the test current from a second thermo wire via a second terminal during the test mode; a reference resistor for generating a reference voltage, which reference resistor is arranged in the current circuit of the test current; and a processing unit coupleable to the first and second terminals and to the reference resistor, and configured to compare a voltage drop caused by said test current between the first and second terminal with the reference voltage.

Abstract: A thermo wire testing circuit, comprising: a current source terminal for supplying a test current to a first thermo wire via a first terminal during a test mode; a current drain terminal for receiving the test current from a second thermo wire via a second terminal during the test mode; a reference resistor for generating a reference voltage, which reference resistor is arranged in the current circuit of the test current; and a processing unit coupleable to the first and second terminals and to the reference resistor, and configured to compare a voltage drop caused by said test current between the first and second terminal with the reference voltage.

Abstract: Control electronics (E) for a two-wire process device, which two-wire process device can be connected to a two-wire loop (2L), wherein the control electronics (E) comprises an input circuit (ES) and a control unit connected to the input circuit (ES), wherein the input circuit (ES) is used in a first operating mode to set a current and/or voltage in the two-wire loop (2L) by means of a control signal (CS) transmitted by the control unit (SE), wherein the input circuit (ES) is used in a second operating mode to automatically, in particular independently of the control unit (SE) or independently of the control signal (CS) transmitted by the control unit (SE), to set the current and/or the electric voltage in the two-wire loop (2L).

Abstract: A delta-sigma D/A converter, by which a digital valued, input signal is convertible into a binary, clock signal time discrete, output signal. By forming an average value of the output signal over a number of clock signal cycles, an analog value of the input signal can be displayed. The delta-sigma D/A converter is embodied in such a manner that, in use, it provides the output signal by serial arrangement of signal patterns of a set of signal patterns, wherein the signal patterns of the set are, in each case, binary, clock signal time discrete and extend over a signal pattern cycles total of a plurality of clock cycles. At least two signal patterns of the set have mutually different signal pattern average values, which are formed over the respective signal pattern cycles total, and all signal patterns of the set have, in each case, essentially the same number, especially exactly the same number, of edges.

Abstract: A delta-sigma D/A converter, by which a digital valued, input signal is convertible into a binary, clock signal time discrete, output signal. By forming an average value of the output signal over a number of clock signal cycles, an analog value of the input signal can be displayed. The delta-sigma D/A converter is embodied in such a manner that, in use, it provides the output signal by serial arrangement of signal patterns of a set of signal patterns, wherein the signal patterns of the set are, in each case, binary, clock signal time discrete and extend over a signal pattern cycles total of a plurality of clock cycles. At least two signal patterns of the set have mutually different signal pattern average values, which are formed over the respective signal pattern cycles total, and all signal patterns of the set have, in each case, essentially the same number, especially exactly the same number, of edges.