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 state of the PROFINET communication.

Cyclic data 1:Fig.31: TwinCAT tree - Inputs for information

The variable DevState. contains information about the phys. communication state of the controller, such as the link state or whether the send resources are still sufficient.

The other variables are the collective PROFINET error and the collective PROFINET state. Both show the number of devices for which a problem has occurred or for which a diagnosis is available. This means that the Error variable indicates possible problems when establishing a connection or reasons for an interruption. The diagnosis variable provides state information about an existing connection.

The output variable DevCtrl currently has no function.

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