Abstract: A safety switching device for controlling a load having at least one input for receiving an input signal and one output for outputting an output signal, and having an electrical circuit which provides the output signal as a function of the input signal. The electrical circuit is arranged on a printed circuit board and is coupled to at least one setting component for setting an operating parameter of the safety switching device. The surface of the printed circuit board defines a mounting plane, and the at least one setting component has an adjusting element in a housing and is arranged recessed on the printed circuit board so that the housing of the adjusting element intersects the mounting plane.

Abstract: A safety circuit for fail-safe shutdown of a dangerous technical system with a plurality of disconnectable system component groups comprises a plurality of safety switching devices electrically connected to one another in series to form a closed-loop monitoring circuit in which electric monitoring current flows through the safety switching devices. Each of the safety switching devices includes: a fail-safe control unit that detects and evaluates information about a current operating state of any system component group assigned to it; and a current flow adjuster that changes the current flow within the monitoring circuit to interrupt the monitoring circuit in response to detection of a safety command by the safety switching device. The fail-safe control units generate a shutdown signal in response to an interruption of the current flow within the monitoring circuit, which causes the fail-safe shutdown of any of the system component group not already shut down.

Abstract: A safety switching device for controlling a load having at least one input for receiving an input signal and one output for outputting an output signal, and having an electrical circuit which provides the output signal as a function of the input signal. The electrical circuit is arranged on a printed circuit board and is coupled to at least one setting component for setting an operating parameter of the safety switching device. The surface of the printed circuit board defines a mounting plane, and the at least one setting component has an adjusting element in a housing and is arranged recessed on the printed circuit board so that the housing of the adjusting element intersects the mounting plane.

Abstract: A safety switching device for fail-safely disconnecting an electrical load has an input part for receiving a safety-relevant input signal, a logic part for processing the at least one safety-relevant input signal, and an output part. The output part has a relay coil and four relay contacts. The first and second relay contacts are arranged electrically in series with one another. The third and fourth relay contacts are also arranged electrically in series with one another. The first and the third relay contacts are mechanically coupled to each other and form a first group of positively driven relay contacts. The second and the fourth relay contacts are mechanically coupled to each other and form a second group of positively driven relay contacts. The logic part redundantly controls the first and the second groups of positively driven relay contacts to selectively allow, or to interrupt in a fail-safe manner, a current flow to the electrical load, depending on the safety-relevant input signal.

Abstract: An emergency off-switch for triggering an emergency switch-off function has an actuator and two electrical contact points that can be disconnected from one another by the actuator. The emergency off-switch has an active operating state in which the emergency switch-off function can be triggered by moving the actuator, and a passive operating state in which the emergency off-switch is functionless. The emergency off-switch further has a visualization unit having at least a first and a second display state. The emergency off-switch is visually highlighted in the first display state, and the emergency off-switch is neutrally represented in the second display state. The visualization unit adopts the first display state in the active operating state and adopts the second display state in the passive operating state. The emergency off-switch also has a monitoring unit which monitors whether the visualization unit is in the first or in the second display state.

Abstract: A safety circuit for fail-safe shutdown of a dangerous technical system with a plurality of disconnectable system component groups comprises a plurality of safety switching devices electrically connected to one another in series to form a closed-loop monitoring circuit in which electric monitoring current flows through the safety switching devices. Each of the safety switching devices includes: a fail-safe control unit that detects and evaluates information about a current operating state of any system component group assigned to it; and a current flow adjuster that changes the current flow within the monitoring circuit to interrupt the monitoring circuit in response to detection of a safety command by the safety switching device. The fail-safe control units generate a shutdown signal in response to an interruption of the current flow within the monitoring circuit, which causes the fail-safe shutdown of any of the system component group not already shut down.

Abstract: A safety switching device for fail-safely disconnecting an electrical load has an input part for receiving a safety-relevant input signal, a logic part for processing the at least one safety-relevant input signal, and an output part. The output part has a relay coil and four relay contacts. The first and second relay contacts are arranged electrically in series with one another. The third and fourth relay contacts are also arranged electrically in series with one another. The first and the third relay contacts are mechanically coupled to each other and form a first group of positively driven relay contacts. The second and the fourth relay contacts are mechanically coupled to each other and form a second group of positively driven relay contacts. The logic part redundantly controls the first and the second groups of positively driven relay contacts to selectively allow, or to interrupt in a fail-safe manner, a current flow to the electrical load, depending on the safety-relevant input signal.

Abstract: An emergency off-switch for triggering an emergency switch-off function has an actuator and two electrical contact points that can be disconnected from one another by the actuator. The emergency off-switch has an active operating state in which the emergency switch-off function can be triggered by moving the actuator, and a passive operating state in which the emergency off-switch is functionless. The emergency off-switch further has a visualization unit having at least a first and a second display state. The emergency off-switch is visually highlighted in the first display state, and the emergency off-switch is neutrally represented in the second display state. The visualization unit adopts the first display state in the active operating state and adopts the second display state in the passive operating state. The emergency off-switch also has a monitoring unit which monitors whether the visualization unit is in the first or in the second display state.

Abstract: A safety circuit arrangement for failsafe connection or disconnection of a hazardous installation has a control device, which is designed to connect or interrupt, in failsafe fashion, a power supply path to the installation. The safety circuit arrangement also has a signaling device, which is connected to the control device via a two-wire line having a first core and a second core. The signaling device has an actuator, which can change between a defined first state and a second state. Between the two cores is a substantially constant voltage when the actuator is in the second state. A pulse generator in the signaling device causes a voltage dip between the first core and the second core in order to generate a defined pulsed signal comprising a plurality of signal pulses on the lines, when the actuator is in the defined first state.

Abstract: A signaling device for a safety circuit has an input part for receiving an external state variable, at least one switching element and a control part. The control part controls the at least one switching element as a function of the external state variable, such that a signal applied to the input is communicated to the output. According to one aspect of the invention, the input of the switching element is internally connected to a fixed potential, preferably a fixed High potential. In a safety circuit for turning off a hazardous installation, such signaling devices are connected in series with one another to a safety controller. In such an arrangement, the control part of the downstream second signaling device also controls its switching elements as a function of the output of the first signaling device.

Abstract: The invention relates to a safety switching apparatus and to a method for safely switching on and off an electrical load, in particular an automated installation. The apparatus comprises a first port for a first signaling element, a second port for a second signaling element, a first switching device coupled to a first switching activator, and a second switching device coupled to a second switching activator. A time monitoring apparatus activates the first and the second switching activators only if a time between an actuation of the signaling elements is smaller than a predetermined maximum duration. The activation of the switching activators in turn causes the switching devices to be switched-through and thus the load to be switched on. For the activation of the switching activators, a first and a second switching element, which are each arranged in series with the switching activators, need to switched-through.

Abstract: A safety switching device comprises a position encoder, such as a potentiometer, for user selection of an operational quantity, such as an operating mode. The position encoder has a first terminal, a second terminal, and a tap moveable through a plurality of positions. A total impedance is defined between the first terminal and the second terminal. A first partial impedance is defined between the first terminal and the tap, and a second partial impedance is defined between the tap and the second terminal. An arrangement for determining an instantaneous position of the tap comprises a first evaluation circuit designed to determine a first measurement value representative of the first partial impedance, and a second evaluation circuit designed to determine a second measurement value representative of the second partial impedance. At least one from the first and second evaluation circuits is designed to determine the instantaneous position of the tap by means of the first and second measurement values.

Abstract: A device for reliably monitoring a closed position of two parts which can move relative to one another has an actuator and a sensor. The device is particularly used for monitoring the closed position of a protective door installed for safeguarding a technical installation which operates in an automated fashion. The sensor has a receiver circuit at an input side, which circuit generates a defined receiver circuit signal when a switching distance between the sensor and the actuator is fallen short of. A detector circuit provides an enable signal when the defined receiver circuit signal is present. According to one aspect of the invention, a test element is provided for selectively suppressing the defined receiver circuit signal.

Abstract: A safety switch for reliably switching off a dangerous device has an actuator which can be moved between a first position and at least one second position. It also has a detector for detecting the actuator in at least one of the said positions. The detector comprises a transponder with an individual transponder identification and a reading unit for reading out the transponder identification. The transponder and the reading unit are arranged relative to one another such that the reading unit is capable of reading out the transponder in the first position of the actuator but not in its second position.

Abstract: The invention relates to a safety switching apparatus and to a method for safely switching on and off an electrical load, in particular an automated installation. The apparatus comprises a first port for a first signaling element, a second port for a second signaling element, a first switching device coupled to a first switching activator, and a second switching device coupled to a second switching activator. A time monitoring apparatus activates the first and the second switching activators only if a time between an actuation of the signaling elements is smaller than a predetermined maximum duration. The activation of the switching activators in turn causes the switching devices to be switched-through and thus the load to be switched on. For the activation of the switching activators, a first and a second switching element, which are each arranged in series with the switching activators, need to switched-through.

Abstract: A safety switching device comprises a position encoder, such as a potentiometer, for user selection of an operational quantity, such as an operating mode. The position encoder has a first terminal, a second terminal, and a tap moveable through a plurality of positions. A total impedance is defined between the first terminal and the second terminal. A first partial impedance is defined between the first terminal and the tap, and a second partial impedance is defined between the tap and the second terminal. An arrangement for determining an instantaneous position of the tap comprises a first evaluation circuit designed to determine a first measurement value representative of the first partial impedance, and a second evaluation circuit designed to determine a second measurement value representative of the second partial impedance. At least one from the first and second evaluation circuits is designed to determine the instantaneous position of the tap by means of the first and second measurement values.

Abstract: A signaling device for a safety circuit has an input part for receiving an external state variable, at least one switching element and a control part. The control part controls the at least one switching element as a function of the external state variable, such that a signal applied to the input is communicated to the output. According to one aspect of the invention, the input of the switching element is internally connected to a fixed potential, preferably a fixed High potential. In a safety circuit for turning off a hazardous installation, such signaling devices are connected in series with one another to a safety controller. In such an arrangement, the control part of the downstream second signaling device also controls its switching elements as a function of the output of the first signaling device.

Abstract: A safety switch for reliably switching off a dangerous device has an actuator which can be moved between a first position and at least one second position. It also has a detector for detecting the actuator in at least one of the said positions. The detector comprises a transponder with an individual transponder identification and a reading unit for reading out the transponder identification. The transponder and the reading unit are arranged relative to one another such that the reading unit is capable of reading out the transponder in the first position of the actuator but not in its second position.

Abstract: A device for reliably monitoring a closed position of two parts which can move relative to one another has an actuator and a sensor. The device is particularly used for monitoring the closed position of a protective door installed for safeguarding a technical installation which operates in an automated fashion. The sensor has a receiver circuit at an input side, which circuit generates a defined receiver circuit signal when a switching distance between the sensor and the actuator is fallen short of. A detector circuit provides an enable signal when the defined receiver circuit signal is present. According to one aspect of the invention, a test element is provided for selectively suppressing the defined receiver circuit signal.