PROFINET gateways for remote I/O systems - 4 PROFINET functions in focus

System redundancy S2 - Process reliability through communication with redundant controllers
System redundancy S2 describes the communication between a device and two controllers in a redundant configuration. The controllers each establish their own logical connection to the device, which is called an Application Relationship (AR). The lottery principle gives one controller the active role. If a switchover occurs, the passive controller with its AR to the field device takes over control seamlessly - typically in less than 200 milliseconds.

In this context, the PROFINET gateway of the LB or FB remote I/O systems from Pepperl+Fuchs assumes the role of a field device and maps all connected sensors and actuators in the controller. This means that the process controller remains in operation even in the rare event of a controller failure and the redundancy switchover prevents unwanted system downtime.