Cyclic data

There are several cyclic process data directly below the PROFINET controller protocol. These data are only exchanged between the PROFINET driver and the system manager. They provide general information about the status of the PROFINET communication.

The ‘DevState’ variable contains information about the physical communication status of the controller, such as the link status or whether the transmission resources are still sufficient.

The other variables are the collective PROFINET error and the collective PROFINET status. Both indicate the number of devices in which a problem has occurred or in which a diagnosis is available, i.e. the error variable indicates possible problems with the establishment of a connection or reasons for an abort. The diagnostic variable provides status information about an existing connection.

The ‘DevCtrl’ output variable currently has no function.

For further information, please also read the chapter entitled ‘Box States'.