Abstract: An apparatus includes a communication device and an evaluation unit, wherein the communication device can be linked to a communication bus and can receive secure telegrams by way of the communication bus, and wherein a secure telegram includes user data and CRC data in each instance. In at least one embodiment, in order to improve the communication within the secure bus system, the evaluation unit can determine an error rate from received secure telegrams by way of a CRC check and if a threshold value of the error rate stored in the evaluation unit is exceeded, can effect a secure state of the apparatus.

Abstract: An absorber unit is disclosed for increasing the noise immunity of a system bus. In order to improve the noise immunity of the system bus, the system bus is designed such that communication can take place in a defined communication frequency spectrum. In at least one embodiment, the absorber unit includes a high-pass filter and an absorber resistor. The high-pass filter can be connected to the system bus on the input side and to the absorber resistor on the output side and is dimensioned such that is has a low-impedance effect for noise signals above the communication frequency spectrum so that those signals are absorbed by the absorber resistor.

Abstract: In a method for forming a CRC value using a plurality of data blocks, the CRC protection can be improved even further by virtue of the fact that, in order to form the CRC value, data blocks which are not transmitted to a receiver or have not been transmitted to a receiver are placed in front of data blocks which are transmitted to the receiver or have been transmitted to the receiver.

Abstract: A communication component is disclosed for communication via an AS-i line. In order to provide an improved AS-i communication component for communication via an AS-i line, it is proposed in at least one embodiment that a standard AS-i signal and an extended AS-i communication signal are sent and/or received via an AS-i line using a shared communication component.

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: A communication method and a master-slave system, for a field bus configures according to the AS-interface standard, are disclosed. Such a master-slave system for a field bus configured according to the AS-interface standard connects a master to a number of slaves. This field bus forms a first communication channel for the master and the slaves. In at least one embodiment, the master communicates with the slaves in sequence via telegrams, which are each uniquely associated with one of the slaves. Between the master and slaves a second communication channel is provided in at least one embodiment, via which one of the telegrams may be repeated, in addition to the first communication channel, if the communication of said telegram via the first communication channel has failed.

Abstract: An absorber unit is disclosed for increasing the noise immunity of a system bus. In order to improve the noise immunity of the system bus, the system bus is designed such that communication can take place in a defined communication frequency spectrum. In at least one embodiment, the absorber unit includes a high-pass filter and an absorber resistor. The high-pass filter can be connected to the system bus on the input side and to the absorber resistor on the output side and is dimensioned such that is has a low-impedance effect for noise signals above the communication frequency spectrum so that those signals are absorbed by the absorber resistor.

Abstract: A communication method and a master-slave system, for a field bus configures according to the AS-interface standard, are disclosed. Such a master-slave system for a field bus configured according to the AS-interface standard connects a master to a number of slaves. This field bus forms a first communication channel for the master and the slaves. In at least one embodiment, the master communicates with the slaves in sequence via telegrams, which are each uniquely associated with one of the slaves. Between the master and slaves a second communication channel is provided in at least one embodiment, via which one of the telegrams may be repeated, in addition to the first communication channel, if the communication of said telegram via the first communication channel has failed.

Abstract: A command switch or and emergency stop switch is disclosed, which includes an actuator and a contact sensor which is separated therefrom. The actuator includes housing and a tappet, which is guided therein and which has a rest position and an actuation position. The contact sensor includes an open switch element which can be placed in the actuation position by way of the tappet in a tensed position. In at least one embodiment, the command switch also includes an additional switch element which is provided with a first switch piece and a second switch piece, which are applied to the actuator in a separated manner and in/on the contact sensor. The additional switch element only closes when the contact sensor is secured to the actuator. The switch pieces of the additional switch element are separated from each other in a compulsory and advantageous manner by the separated embodiment of the command switch enabling them to be secured to different components of the command switch.

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: Coupling of bus systems is simplified. To this end, a coupling device is disclosed that is used to couple two field buses to a periphery bus. The periphery bus can be used to connect input/output modules for the central monitoring or processing of data. For example, the coupling device can be configured in terms of the transfer of standard data and security-relevant data between the three bus systems.

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.

Abstract: The invention relates to a safety switch arrangement for switching the power supply of a tool on and off by means of at least two actuators. The actuators are connected to a code generator. The code generator can issue a numerical word divided into two partial words, the values of which can be influenced by a respective one of the at least two actuators. If the actuators are activated, the values for the partial words are changed continuously. As a result of the deactivation of an actuator, the assigned partial word assumes a fixed, predetermined value. In order to check the switching states of the actuators, the partial words are read synchronously into an evaluation unit. The power supply of the tool is switched “on” only when the at least two actuators are activated to the “on” state and the partial words correspond to the predetermined fixed value.

Abstract: To compensate for the temperature dependence of a resonant circuit, it is known to use an a.c. current source, with which the resonant circuit is excited in dependence upon the ohmic resistance of the coil conductor material. The task of compensating for temperature may to be solved without a costly closed-loop control process and with few losses. A magnetically coupled second coil is connected in parallel with the first coil to be compensated, and an NTC thermistor is connected in series with one of the two coils so that the series connection is connected in parallel with the other of the two coils. The NTC thermistor is selected so that, in conjunction with the two variable sized ohmic resistors of the two coils, the circuit arrangement has a specified total ohmic resistance, which is substantially independent of temperature.

Abstract: This invention concerns an inductive proximity switch having an oscillator and a resonant circuit which is dampable by outside objects, as well as an electronic switch controllable by the voltage across the resonant circuit. From the signal of the electronic switch a switching hysteresis is derived. A device for changing the frequency, when the resonant circuit is damped, as a function of the signal of the electronic switch allows the adjustment of the hysteresis in such a way that there is essentially no effect on the sensitivity of the oscillator.