openSAFETY is basically notable for its data transfer definitions, for the high-level configuration services it provides, and especially for its encapsulation of data that is relevant to safety into an extremely flexible telegram format. Indeed, in all applications, openSAFETY uses a frame with a uniform format, no matter whether for payload data transfer, or for configuration or time synchronization purposes. As variable as it is economic, frame length is contingent on the amount of data to be transferred. The safety nodes on the network automatically recognize the content, i.e. frame types and lengths do not have to be configured.
Automatic safe parameter distribution
One special openSAFETY highlight is the automatic safe distribution of parameters: the protocol enables storing all configuration details for safety applications, such as e.g. light curtains, in the safety controller. If a device is exchanged, the safety controller automatically and safely loads the stored configuration onto the swapped application – i.e. users do not need to manually configure the new node when they replace a safety device.
No faults go undetected
openSAFETY uses checksum procedures to perpetually examine whether transferred data content is incomplete, and constantly monitors the data transfer rate. Due to extremely short cycle times, failures are detected almost without any delay. Since all data traffic irregularities will thus be recognized, even unsafe networks do not compromise safety functionality. The following paragraph points out which type of transmission errors may occur, and explains the mechanisms openSAFETY uses to identify or prevent these faults.