A method for real-time-based transfer of data telegrams from a verified transmitter to a verified receiver without delays, wherein (a) each data telegram to be transferred from the transmitter to the receiver is provided with an additional data index, (b) each received data is stored in a memory, along with the associated additional data index, (c) after elapse of a predetermined time interval, or after transference of a defined number of data telegrams, the transmitter transfers a second time data telegram already transferred to the receiver which has an additional signature, and where the data telegram transferred the second time is additionally encrypted by the transmitter, and (d) after receiving the signed data telegram transferred the second time, the signed data telegram transferred the second time is compared with the corresponding data telegram stored in the memory to verify the transmitter, and where (e) steps a) to d) are repeated.

A method for real-time-based transfer of data telegrams from a verified transmitter to a verified receiver without delays, wherein (a) each data telegram to be transferred from the transmitter to the receiver is provided with an additional data index, (b) each received data is stored in a memory, along with the associated additional data index, (c) after elapse of a predetermined time interval, or after transference of a defined number of data telegrams, the transmitter transfers a second time data telegram already transferred to the receiver which has an additional signature, and where the data telegram transferred the second time is additionally encrypted by the transmitter, and (d) after receiving the signed data telegram transferred the second time, the signed data telegram transferred the second time is compared with the corresponding data telegram stored in the memory to verify the transmitter, and where (e) steps a) to d) are repeated.

A segment of a two wire combined power and data network for automation has a trunk, a spur mounted thereon and a fault protection device. The fault protection device includes a controller adapted to monitor the spur current, and isolation means to fully or partially isolate the spur from the trunk upon receiving of an activation signal from controller. The controller comprises a failure status determination algorithm comprising an intermittent fault count over time step and a fault duration step. The intermittent fault count step is satisfied if a pre-determined number of separate faults are detected over a first time period. The fault duration step is satisfied if a fault is detected which persists for longer than a second time period. The controller issues the activation signal upon determination of a failure status on the spur which satisfies the intermittent fault count and/or the fault duration step of the algorithm.