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.

The present disclosure relates to a method for verifying the origin of electronic modules of a field device. Each manufacturer of an electronic module classified as trustworthy is assigned a key pair. Public keys classified as trustworthy are stored in a list in the field device. Each electronic module contains the public key of the manufacturer and a manufacturer signature. The manufacturer signature confirms the public key as trustworthy. When an electronic module is exchanged or added, the field device checks whether that module has a key pair and a manufacturer signature, whether the public key of the manufacturer of the electronic module is listed in the list with the public keys of the manufacturers classified as trustworthy, whether the manufacturer signature matches the manufacturer and the electronic module, and whether the electronic module is in possession of a correct private key.

A system includes a module having at least one input/output (I/O) channel. The system also includes a terminal block having terminals configured to provide electrical connections for the at least one I/O channel. The system further includes a barrier assembly having one or more intrinsic safety (IS) barriers. Each IS barrier is configured to receive at least one data or power signal, limit an amount of energy in the at least one data or power signal, and output the at least one energy-limited data or power signal. Each IS barrier includes at least one limiter circuit configured to limit the amount of energy in the at least one data or power signal. Each IS barrier is configured to be mounted on the terminal block. Each IS barrier could be configured to provide galvanic isolation between multiple devices or systems coupled to the IS barrier. Each limiter circuit could include a current limiter.

A system includes a module having at least one input/output (I/O) channel. The system also includes a terminal block having terminals configured to provide electrical connections for the at least one I/O channel. The system further includes a barrier assembly having one or more intrinsic safety (IS) barriers. Each IS barrier is configured to receive at least one data or power signal, limit an amount of energy in the at least one data or power signal, and output the at least one energy-limited data or power signal. Each IS barrier includes at least one limiter circuit configured to limit the amount of energy in the at least one data or power signal. Each IS barrier is configured to be mounted on the terminal block. Each IS barrier could be configured to provide galvanic isolation between multiple devices or systems coupled to the IS barrier. Each limiter circuit could include a current limiter.

The invention relates to a connection module for field devices in the explosion-protected area, having a housing with a plurality of controller-end terminals to connect to at least one input/output module and with field-end terminals to connect to the field devices. The connection module is characterized in that different resistors are present in the housing to provide intrinsically safe pairs of field-end terminals with different characteristic values, said resistors being hardwired in the housing to different field-end terminals and/or controller-end terminals.

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.