Henry Ford would have been thrilled with Industry 4.0. At the beginning of the last century, the pioneer of automotive construction was the first to develop and apply many approaches of modern production technology. Apart from assembly line production, also resource efficiency, automaton as well as production data acquisition and analysis were key concepts in the Ford Motor Company – concepts that, today, under the umbrella term ‘Industry 4.0’, are to open up new possibilities for production in the Age of Information. And for this, communication plays a major role.
Presently, Industry 4.0 is one of the most debated topics in the international industry. Often referred to as the ‘fourth industrial revolution’, it is said to bring radical change to the world of production. Efficiency, flexibility and productivity are believed to increase significantly. The foundation is the networking of machines and plants into Cyber-Physical Systems (CPS). Thanks to digital networking and high flexibility, automated production down to lot size 1 is believed to be possible. Even if there are presently many uncertainties about how exactly Industry 4.0 will actually work and which new standardisations it will require, one thing is for sure: Communication is of major importance.
Communication Across All Levels
One of the visions connected to Industry 4.0 is not new: Communication across all levels of data processing within one company should be possible. From field level via control, process control and supervisory level, up to company level, data should offer seamless availability.
However, there are several obstacles to the communication from ERP level down to the sensors on the machine. At control level, a PLC processes the data of the connected inputs and outputs at field level, but usually transmission of all data to the process control level is not provided for. The sensor data is processed in the PLC program and used to control the actuators. If and which data the PLC transfers upwards to the process control level needs to be defined in the PLC program. If additional data is to be made available to the higher levels in an existing plant, the PLC program needs to be changed. This reduces flexibility while direct access to the sensor data is only possible to a limited extent.
Potentials Of Increasing Efficiency
One of the advantages of Industry 4.0 is said to be resource efficiency. This can be illustrated using the example of compressed air consumption - the most expensive form of energy applied in the manufacturing industry. If sensors are used to detect the consumption of compressed air on the machines and plants, leaks can be identified; this makes it easy to reduce unnecessary costs. Compressed air sensors are applied on many machines while the PLC monitors the machines' readiness for operation. In most cases, this only requires checking if the air pressure is sufficient – ie: if it is above a certain threshold.
Other values, such as fluctuating pressures or pressure drops, are registered by the sensor, but not analysed in the PLC. If compressed air monitoring for all consumers in a production plant was to be introduced, the PLC would need to be changed and the corresponding values need to be made available for the process control level – which is usually too much effort.
A further example for an increase in efficiency is condition-based maintenance of machines. Sensors on machines can easily detect vibration of bearings. This vibration makes it very easy to determine if a bearing will soon be defective, which could lead to a standstill of the machine. But, also in this case, it is important that a corresponding machine monitoring system can access this sensor data. This could enable maintenance of machines according to their condition. A bearing will be replaced exactly when damage is imminent. If the machine is repaired when the bearing is already damaged, the machine stands still, causing production losses and additional costs. Regular replacement at fixed maintenance intervals also increases costs since, in this case, bearings that could still be used for a very long time are also replaced. Also for this application, coherent communication of sensor data is indispensable.
Y Communication Omitting The PLC
Many of the current concepts discussed within the scope of Industry 4.0 require coherent communication. In many companies, the responsibility for the different levels constitutes a further obstacle: While the electrical and automation technology department is responsible for the process control, control and field level, the IT department is responsible for the business software – two departments with different priorities and concepts.
Today, ERP system suppliers offer solutions to optimise production. One condition for this, however, is that the corresponding data is available. In order to overcome the above-mentioned obstacles, a tool is needed that makes data available throughout the company. The demands regarding such a tool are numerous: Firstly, it should be able to process different data sources and cooperate with all protocols that are generally used in automation technology.
In this context, real-time communication via different interfaces both with synchronous and asynchronous data transmission must be possible. The independence from operating systems and hardware as well as the possibility to cope with large data volumes are further requirements.
One solution answering all above-mentioned requirements is ifm's Linerecorder. This system consists of several software modules allowing the implementation of coherent communication. The Linerecorder Agent Connectivity Port (LR Agent CP), for example, is a software gateway allowing bidirectional communication between a great number of different interfaces. This allows communication between SAP systems and data from units at field, control and process control level. Linerecorder Sensor allows to capture and transmit all IO-Link sensor data. This overcomes the above-mentioned obstacle because this system transmits the sensor data to the ERP system by omitting the PLC. This direct path for sensor data by omitting the control level is referred to as ‘Y communication’ in ifm terminology because, splitting up like the letter Y, the data reaches, on the one hand, the PLC, and, on the other hand, directly the company management level.
The agent solution offered by Linerecorder also exists in an embedded version that is independent of the operating system. It can be installed directly to sensors, actuators and evaluation electronics. One example for the latter are Industry 4.0 gateways with 8 IO-Link interfaces. IO-Link represents the lowest communication level that makes it possible to transmit sensor parameters and status messages in addition to the process values. Therefore, Linerecorder Agent is a bridge between the superposed system and the machine periphery.
Many Possible Applications
One important basis for communication is the integration of sensors. As described above, Linerecorder processes the data from IO-Link sensors without any problem. This simple interface makes it possible that the sensors can transmit the data both to the higher-level PLC and – on the second Y branch – to an ERP system. The specialists from ifm electronic are convinced that this kind of integration of intelligent sensors is the key to the future; and this applies in particular to Industry 4.0. This is why all new sensors from the company come with a standard IO-Link interface. Currently, ifm electronic's product range contains about 300 IO-Link sensors, and every year, 100 to 150 new models are added.
The Linerecorder system enables many applications that were not possible so far due to missing communication or which would otherwise have caused a lot of trouble and expenses. With Linerecorder Smartobserver, the software framework offers a system for visualisation and monitoring that enables convenient monitoring of machines and plants. This allows the above-mentioned condition-based maintenance. The Smartobserver's visualisation can be adapted to the user's requirements. Monitoring and recording energy consumption values with the Smartobserver allows evaluations which are required for a certification according to ISO 50001. Finally, all data is also available for higher-level systems at ERP level.
Communication As A Key
Trouble-free communication between all different components and systems is the most important condition for Industry 4.0. It seems very unlikely that communication across all levels will be standardised a system like Linerecorder is available as a gateway between different levels and systems and makes it possible for Industry 4.0 to become reality.