Abstract: For operating a plant having at least one open- and/or closed-loop heating control device for heating elements, values for an energy consumption and/or an instantaneous power draw of the heating elements are determined, without using measured values for electric currents, on the basis of characteristic parameters of the heating elements and on the basis of values of open- and/or closed-loop control variables for the open- and/or closed-loop control of a heat output of the heating elements. This enables the network load to be determined, reported and optimized by the open- and/or closed-loop heating control devices even without complex and therefore expensive measuring devices in the open- and/or closed-loop heating control device.

Abstract: At least one embodiment of the invention relates to a fieldbus system, in particular for use in an explosion-hazard area. The fieldbus system, in at least one embodiment, has a plurality of bus line sections with bus lines; an isolating element, by which in each case two of the plurality of bus line sections are coupled to one another and which galvanically isolates the bus lines of the two bus line sections from one another such that this prevents any direct current flowing between the bus lines of the two bus line sections and communication signals are transmitted between the two bus line sections; and a supply source for each of the bus line sections, in order to provide an electrical power supply for field devices which can be connected to the respective bus line section.

Abstract: At least one embodiment of the invention relates to a fieldbus system, in particular for use in an explosion-hazard area. The fieldbus system, in at least one embodiment, has a plurality of bus line sections with bus lines; an isolating element, by which in each case two of the plurality of bus line sections are coupled to one another and which galvanically isolates the bus lines of the two bus line sections from one another such that this prevents any direct current flowing between the bus lines of the two bus line sections and communication signals are transmitted between the two bus line sections; and a supply source for each of the bus line sections, in order to provide an electrical power supply for field devices which can be connected to the respective bus line section.

Abstract: Data transfer between a secure computer and a number of input/output units occurs via a bus control unit connected to the secure computer and a serial bus system. The bus control unit cyclically activates the input/output units connected to the bus system and transfers multi-bit message to the respective activated input/output unit. In order to produce a data transfer method which enables security/related signals to be transmitted via a non-error-protected bus system, at least one of the input/output units is designed as a security unit. Further, the multi-bit message transferred to the security unit has at least one checkbit. The security unit interprets the transferred multi-bit message as correct only if the checkbit alternates within a predefined monitoring period.

Abstract: Two measures are provided in order to allow a serial bus system to be operated such that it is resistant to interference and defects, and such that it operates with low power consumption. Firstly, each transmitted digital signal is interpreted as a logic zero or a logic one, respectively, when a first or a second predetermined current waveform, respectively, is applied to a bus line. Secondly, the bus system is operable in an energy saving mode, in which either no data transmissions at all are made, or in which data transmissions are made only rarely, between the individual bus modules.

Abstract: Two measures are provided in order to allow a serial bus system to be operated such that it is resistant to interference and defects, and such that it operates with low power consumption. Firstly, each transmitted digital signal is interpreted as a logic zero or a logic one, respectively, when a first or a second predetermined current waveform, respectively, is applied to a bus line. Secondly, the bus system is operable in an energy saving mode, in which either no data transmissions at all are made, or in which data transmissions are made only rarely, between the individual bus modules.