Energy management and responsible handling of resources is currently the number one topic in industry. In light of this, the Automation Initiative of German Automobile Manufacturers (AIDA) asked the PROFIBUS organization and PROFINET International (PI) to provide functions and mechanisms for PROFINET that support energy-efficient production.
In response, PI is working on a vendor-neutral energy savings profile called PROFIenergy. The objective is to develop a uniform (standardized) interface for data exchange between a controller and a wide range of devices with energy savings options. The profile will be used for exchanging data and commands, but will not contain any logic functions in terms of process control. The first release of PROFIenergy should be available by the end of this year (2009).
The PROFIenergy roadmap.
Energy-efficient production means more than just the use of variable-speed drives and efficient motors. The question going forward is how to selectively place complete production lines or portions thereof into stand-by mode during unproductive times. Ethernet networks such as PROFINET play a key role in this.
Main switch OFF: all production activities cease and the factory lights go out. This is possible during idle times, such as weekends or factory holidays, in almost every facility around the world. But what happens during shorter breaks? Here, the equipment continues running and consumes energy, even in the absence of value-adding activities or productive results.
For example, a bodyshop factory in the automotive industry continues to demand 20 kW of power during idle times. For this reason, shutting down the entire facility on the weekend is not sufficient.
Rather, it is worthwhile to selectively switch off individual components or portions of the plant during production, if they are not required at the moment. When considered over an extended time period, switching off a device for just 30 seconds can be profitable in certain cases, such as for lasers.
This could significantly improve the energy balance of a production unit. In today's automotive industry, several models already run over the same production lines. Accordingly, it would be possible to respond to fluctuations in sales of individual models by selectively shutting down model-specific portions of the plant.
However, the current approach of disconnecting production components from the supply system using one or more 'main' switches, that is, deactivating different production units with a high degree of selectivity, is not sufficient for this purpose. Permanently wired switching paths for permanently defined production areas are simply too inflexible to fulfill the new requirements for energy efficiency.
German automobile manufacturers, in particular, have recognized this fact and are currently searching intensively for concepts and solutions that will improve the energy balance at both existing and future factories.
The launch of PROFINET IO for plant communication in November 2004 represented a decisive step in the commitment to modern Ethernet technology: According to the conceptions of the Automation Initiative of German Automobile Manufacturers (AIDA), each plant component " whether an industrial robot, a converter, a process control system, or an I/O module " should be accessible in the future via a uniform and comprehensive communication infrastructure, ideally through Ethernet-based protocols such as PROFINET.
Each component of the higher-level control system or the line PLC can then be selectively activated and controlled via the IP address and the device name. In short: The decision to introduce PROFINET laid the foundation for a new and forward-looking energy management.
Future-looking energy management means: switching off equipment is no longer accomplished by means of the conventional and very 'coarse' main switch method but rather by means of the network. The general supply network of components remains activated, and the components, when initiated by a 'network command', pass into a defined energy-saving mode.