Plant data is process data from the operation of a customer plant, that is permanently saved from the time of commissioning. Process data represents process variables in a building. The data is continuously changed by the environment, automation station and, in the event of physical outputs, the operator. Most process data is volatile. Few process data, such as adaptive control parameters and runtime totalization counts, remains available following a restart or power failure of the automation station. Process data can be archived as plant data.