Patent ID: 7152188

Claim:
A system for protected data transmission in ring-shaped bus systems, comprising a control unit ( 1 ) which sends output data and checking signals for a control process to peripheral units ( 4 , 7 , 8 , 9 , 12 ), a peripheral monitoring unit ( 4 ) which has a first transfer unit ( 5 ) for monitoring the transmitted data and a second transfer unit ( 6 ) for monitoring data to be read back into the control unit ( 1 ), and at least one peripheral safety-related unit ( 9 ) for receiving or transmitting safety-related data, in which data are temporarily stored for output, which has a checking logic ( 11 ) for monitoring the temporarily stored data and an output unit ( 10 ) for outputting the temporarily stored data, the temporarily stored data being monitored by the checking logic ( 11 ) in such a manner that, in the case of a fault, a safe state of the output unit ( 10 ) for the control process is initiated, the first transfer unit ( 5 ) monitoring the data sent out by the control unit ( 1 ), in such a manner that, in the case of a fault, release data for the peripheral safety-related unit ( 9 ) are suppressed or deleted so that the faulty data do not reach the control process, particularly data transmission sequences, wherein the input data of the peripheral safety-related unit ( 9 ) and its temporarily stored data are read back via the second transfer unit ( 6 ), whereby the peripheral safety-related unit ( 9 ) reads back the temporarily stored data via a bus unit ( 23 ), whereby the peripheral safety-related unit ( 9 ) comprises a further bus unit ( 22 ) so that the peripheral safety-related unit ( 9 ) has redundant input channels ( 24 , 25 ) and thus redundantly monitors the connected control process and can detect a fault.