Patent ID: 7430690

Claim:
A peripheral safety-related unit in a system for protected data transmission with a ring-shaped bus, comprising: two bus units ( 22 , 23 ), to forward the output data of the bus unit ( 22 ) also to the input section of the other bus unit ( 23 ) in order to be able to fetch information from a control process via redundant input channels ( 24 , 25 ) and in order to provide the output data of a peripheral monitoring unit ( 4 ) for read-back, said two bus units being connected in series to said ring-shaped bus, wherein the output information from a first bus unit of said two bus units is mapped via an input section of the other bus unit of said two bus units in addition to said fetching of information from the control process via said redundant input channels, a buffer ( 27 ) in which the output data are temporarily stored before their release, an output logic ( 28 ) via which the temporarily stored data are output, and a checking logic ( 11 ) which decides whether the data stored in the buffer ( 27 ) are output via the output logic ( 28 ).