Patent ID: 8321613

Claim:
A method for secure transmission of process data to be transmitted cyclically in a cyclical data transmission to be performed protocol-specifically via a transmission channel between at least one user functioning as a master and at least one user functioning as a slave that are connected to the transmission channel, the method comprising: assigning to each slave during a data transmission cycle, within a transmission protocol frame, a time slot that can always accommodate the same number of bits independently of the data to be transmitted; and generating and transmitting a first set of protection data, wherein the first set of protection data is for recognizing error-free transmission of safety-relevant process data that is to be transmitted securely during the data transmission cycle from a slave to at least one additional user, or that is to be transmitted securely during the data transmission cycle from a user to at least one slave, wherein the process data to be securely transmitted is embedded together with the respective first set of protection data into the time slot assigned to the respective slave and transmitted with it, wherein the time slots assigned to users that can handle the safety-relevant process data are arranged inside the transmission protocol frame ahead of time slots assigned to users that cannot handle the safety-relevant process data.