Ethernet in mechanical engineering
Efficient Production by effective communication
Nowadays, all large companies wish to speak the same language, as this the the precondition for an effective and trouble-free course of business.Unfortunately, it is easier to talk about flawless communication than to implement it.With increasing complexity of the company, it represents an increasingly major challenge. The following text deals with the use of Ethernet in mechanical engineering.
Individual Communication via Ethernet
In the same way as with the human brain and its linkages of synapses, it is also important for companies that the individual business areas are connected to each other to enable or facilitate communication. And in the same way as the human brain of an individual, different branches depend on different types of communication. Especially in the industry branch of mechanical engineering, fast and stable communication must be guaranteed. Ethernet offers this capability.
What is Ethernet?
The so-called LAN technology is understood as Ethernet. LAN means Local Area Network, thus a local network. Devices connected to a local network can send or receive data in the form of data packets. The quantity of data that can be transferred in a given time depends on the range of the respective transfer rates. Starting with 10 Mbps, data volumes can be transported at up to 100 Gbps. Ethernet was developed originally for companies. In the beginning of the 1970s, 3 Mbps could be processed. Nowadays, the data transfer is considerably faster and has also long been used in the private sector.
Common versus Industrial Ethernet
The common Ethernet has a kind of “protective mechanism”. This mechanism prevents other data transfers in case of important and large data transfers, for example from a device to a network - at least until the transfer has been completed. However, this protective mechanism causes a relative time delay. The speed of the data transfer plays a decisive role especially in mechanical engineering. Delays, even if only in the range of seconds, in the worst case can put at risk an entire production process. To prevent this risk, industrial Ethernet has real-time communication capability. Furthermore, a communication network must be stable and reliable. Strong temperature fluctuations, movement, and magnetic fields are some of the operating conditions which must not impair a communication system.
The design of an industrial Ethernet is not pre-defined. Rather, there are various suggested solutions and several practical approaches. The essential characteristics of four established systems are presented in outline:
- SERCOS III: The essential characteristics of this system are real-time capability and sensitivity in regard to disturbances. Additionally, it has a wide range of products distributed by many suppliers.
- PROFINET RT: Because of the modular construction of this concept, the user can determine the manner in which the tasks are solved himself. Profinet CBA permits simultaneous use of real-time communication and component-based use by means of TCP/IP. Profinet IO permits real-time communication and clock-synchronized communication with the decentralized periphery (connection of distributed control systems for a machine to a central processing unit).
- Ethernet/IP: This system is used especially in automation technology. The system is based on TCP and UDP. It supports the communication of office networks and the machine.
- EtherCAT: This system also has real-time capability. EtherCat has specialized in lowering costs for hardware, avoiding accuracy fluctuations, and fast data transfer.
Uniform Protocol, but still different
All concepts are based on TCP/IP and thus share a common protocol. Still, the individual systems differ in regard to different connections and differing mechanisms for control functions. The factors of speed of data transfer and real-time capability are considered the easiest delimitation criteria.
In spite of the increasingly powerful and matured systems, there is still no complete standardization. However, there are several important aspects for the integration: SERCOS III can be seen as Ethernet with multiple connection capability. It has interfaces which permit communication with other systems. This characteristic brings enormous advantages with it, as several functions can be connected with each other.
Final objective: Max. Efficiency
In the end, the result matters for the production. The result is better with more efficiency in advance. The primary goal thus lies in the effect of the technology being used. Accurate planning is always the first step, so that the question of the purpose of the technology should be answered first. Optimal balance in regard to efficiency and flexibility of the individual areas should always be observed. Although this balance cannot be produced with a central program alone, it can be realized by the best possible communication of several programs. To achieve this, separate are as must be continuously developed, and management tasks must be kept to a minimum. Innovative work should be performed where the best knowledge of procedural processes exists. A standardized software solution is required to obtain coordinated communication. Only certain standardizations guarantee a reliable data transfer.