A method operates a safety control in an automation network having a master subscriber which carries out the safety control, at least one first slave subscriber which is assigned a first safety integrity level, and at least one second slave subscriber which is assigned a second safety integrity level. The first safety integrity level and the second safety integrity level differ from each other. A first safety code determination method is assigned to the first slave subscriber and a second safety code determination method is assigned to the second slave subscriber. The first safety code determination method and the second safety code determination method differ from each other. The master subscriber and the first slave subscriber use the first safety code determination method for interchanging a safety data block. The master subscriber and the second slave subscriber use the second safety code determination method for interchanging a safety data block.

A safety system includes a safety unit and at least one safety related participant which comprises a protective device and a first and a second interruptible signal transmission path which can be interrupted together on the occurrence of a non-secure state of the protective device. The safety system includes at least one test signal path which runs through the safety related participant to a safety input of the safety unit starting from an output of the safety unit and comprises at least one of the first and the second interruptible signal transmission paths. The safety related participant comprises an interruption switch arranged in the test signal path and an evaluation unit which is connected to the first signal transmission path and/or to a first switching signal output of the protective device and to the second signal transmission path and/or to a second switching signal output of the protective device.

A safety controller module for providing safety control comprises a non-volatile memory configured for storing a safety control program and one or more processing units configured to execute safety control functions associated with the safety control program to provide independent safety control. The safety controller module further comprises a connector configured to communicatively couple the safety controller module with a non safety controller. The safety controller module is configured to communicate an input and/or an output signal of the safety controller module via the connector to the non-safety controller.

This disclosure provides an automation controller method, system and apparatus including a redundant watchdog utilizing a safety partner controller. According to an exemplary controller, the controller includes a first processing unit, a second processing unit, and an integrated circuit configured to receive as inputs fault indicator signals from the first and second processing units, and the integrated circuit configured to disable I/O communications for a fault condition detected by the first or second processing units.

An intrinsically safe field device of automation technology comprises connection terminals via which a current can be supplied; a sensor element and/or actuator element; field device electronics with a current path between the connection terminals and a voltage regulator incorporated into the current path; and an explosion protection unit comprising at least two controllable switching elements, incorporated into the current path in series, and two threshold value circuits designed such that a first threshold value circuit controls a first switching element as a function of a first threshold value, and a second threshold value circuit controls a second switching element as a function of a second threshold value, such that, upon the first and/or second threshold value being reached, the current is limited to the first and/or second threshold value, and the threshold value circuits are connected in parallel to the voltage regulator.