Online Change for PROFINET

On PLCs which support an online change for devices, not only specific settings of PROFINET devices can be modified during an online change. (See: Re-Parameterization with Online Change). In addition, PROFINET devices, modules, or configurations can be added, removed, or exchanged during operation without stopping the controller application or the production. All other PROFINET devices which are not directly affected by the online change will also remain in operation.

For PROFINET devices which support the "Dynamic Reconfiguration" (DR) feature, this reconfiguration can also be performed without any interruption when adding new modules. While the existing configuration and I/O data remain active, a new connection is established. Then a seamless switch-over to the new configuration is performed before the old connection is removed. This allows for uninterrupted operation.

For devices which do not support the DR feature, or for special settings (e.g., IP address), uninterrupted reconfiguration is not possible. In these cases, the existing connection to this device must be aborted and then re-established with the new configuration.