Abstract: A circuit arrangement for generating a supply voltage with a controllable ground potential level includes a voltage source that provides the supply voltage ungrounded, a control unit that generates an adjustable control d.c. voltage to ground, and an operational amplifier that is connected via its voltage supply terminals to the supply voltage source, where the control d.c. voltage is applied to the inverting input of the operational amplifier, the non-inverting input of the operational amplifier is connected via a resistor network to the voltage source and to a ground terminal and the output of the operational amplifier is fed back to the inverting input via a capacitor.

Abstract: A module for a programmable controller includes a plurality of analog input channels, a control and evaluation device, and input terminals, where for each input channel, the module includes two analog to digital converters, at least four coupling elements and a switchover device, where for each input channel, where an input side of one analog to digital converter is directly or indirectly connected with the input terminals and an output side is connected with the evaluation circuit via a coupling element, where a control input of the switchover device is connected with the switching signal generator via a further coupling element, a signal output of the switchover device is connected with an input side of the other analog-to-digital converter, and where an output side of the other analog-to-digital converter is connected with the evaluation circuit via a further coupling element, where the coupling elements cause electrical isolation.

Abstract: A module for a programmable controller includes a plurality of analog input channels, a control and evaluation device, and input terminals, where for each input channel, the module includes two analog to digital converters, at least four coupling elements and a switchover device, where for each input channel, where an input side of one analog to digital converter is directly or indirectly connected with the input terminals and an output side is connected with the evaluation circuit via a coupling element, where a control input of the switchover device is connected with the switching signal generator via a further coupling element, a signal output of the switchover device is connected with an input side of the other analog-to-digital converter, and where an output side of the other analog-to-digital converter is connected with the evaluation circuit via a further coupling element, where the coupling elements cause electrical isolation.

Abstract: A method and input circuit unit having a first input circuit and a redundant second input circuit, wherein each input circuit includes an input for feeding a measurement current that can be obtained from a signaling device and that can be switched over and operated in such an input circuit unit, where the measurement current causes a voltage drop across a measurement resistor that can be evaluated as a measured value, where a parallel connection of the first and second input circuits causes division of the measurement current among the first and second input circuits, and where at least one input circuit include a device for compensating the decreased voltage drop across the measurement resistor resulting from the division of the measurement current.

Abstract: A circuit arrangement for generating a supply voltage with a controllable ground potential level includes a voltage source that provides the supply voltage ungrounded, a control unit that generates an adjustable control d.c. voltage to ground, and an operational amplifier that is connected via its voltage supply terminals to the supply voltage source, where the control d.c. voltage is applied to the inverting input of the operational amplifier, the non-inverting input of the operational amplifier is connected via a resistor network to the voltage source and to a ground terminal and the output of the operational amplifier is fed back to the inverting input via a capacitor.

Abstract: An input circuit for processing an analog input signal in the form of an analog measurement signal with a modulated additional signal and for converting the input signal into a serial bit stream having a frequency distribution of high levels which is proportional to the input signal, and a method for operating such an input circuit, the input circuit including a device for comparing an instantaneous voltage value of the input signal with a variable comparison value and a device for adapting the comparison value to an instantaneous value of the generated bit stream, is provided.

Abstract: A method and input circuit unit having a first input circuit and a redundant second input circuit, wherein each input circuit includes an input for feeding a measurement current that can be obtained from a signaling device and that can be switched over and operated in such an input circuit unit, where the measurement current causes a voltage drop across a measurement resistor that can be evaluated as a measured value, where a parallel connection of the first and second input circuits causes division of the measurement current among the first and second input circuits, and where at least one input circuit include a device for compensating the decreased voltage drop across the measurement resistor resulting from the division of the measurement current.

Abstract: An input circuit for processing an analog input signal in the form of an analog measurement signal with a modulated additional signal and for converting the input signal into a serial bit stream having a frequency distribution of high levels which is proportional to the input signal, and a method for operating such an input circuit, the input circuit including means for comparing an instantaneous voltage value of the input signal with a variable comparison value and means for adapting the comparison value to an instantaneous value of the generated bit stream is provided.

Abstract: A method is provided for redundantly controlling process of an automation system having at least two controllers in which each controller consecutively carries out a plurality of task blocks, wherein output data which can be transmitted for carrying out the task blocks is stored in a plurality of work regions exceeding the number of task blocks by one. The work regions contain the respective output data for each of the task blocks. The one additional work region, which is the system work region, contains the output data. The method includes transferring the respective previously synchronized content from the system work region into the work region during the start of a task block in the redundant controllers, updating the content while task block is carried out and, if the updated content is identical, then returning the updated content to the system work region again before the next task block is started.