LAN (Local Area Network) / Industrial LAN
In contrast to a WAN (Wide Area Network), a Local Area Network (LAN) is a locally restricted network of computers and controllers. Every computer and every controller networked in the LAN shares the same resources (speed, capacity) without exception, which are made available by the respective host or server.
In enterprise resource planning systems , a LAN is usually owned and used by a single organization/group. It is defined on the basis of the first two layers of the 7-layer model (OSI) and describes the physical (1st layer) and logical (2nd layer) connections. Especially in industrial environments (warehouses, production), local networks are used despite the Internet age. A classic LAN is therefore fundamentally safe from external interference and attacks. To ensure its functionality, there does not need to be a connection to the Internet. Nevertheless, modern warehouse systems use a parallel connection to the Internet, despite the security risk. Firewalls and VPN networks (Virtual Private Network) then provide the necessary security.
A locally configured network works both via cable and wirelessly(WLAN); nowadays, both can be used simultaneously without any problems. The prerequisite is that both transmission media are connected to the same network or hardware; with balanced hardware, it generally operates without latency.
Industrial LAN
The cabling with the industrial LAN does not differ technically from the conventional LAN. Only the properties of the switch, the router, the plug connections themselves, the sheathing of the cable and the two end points of the twisted pair cable are designed to be more robust in contrast to domestic use. Twisted pair cables are standardized and divided into different classes and categories to describe their performance.
Each class or category covers different requirement profiles with specific quality specifications. If different cable classes are used in a network, performance losses are to be expected. The higher the category number, the higher the performance of the network.
LAN Ethernet
Ethernet is a LAN technology that originated in the 1970s. The network technology uses layers one and two of the OSI layer model (LLC and MAC layer / IEEE 802.2 and 802.1) for addressing and access control to the transmission medium. Ethernet is used exclusively for the transmission of data packets. Each packet to be sent is provided with a header and a checksum before being sent to the recipient.
A decisive disadvantage of Ethernet is the transmission technology itself. The technology transports the packaged data without a fixed access grid. With Ethernet, there is therefore no guarantee that the data will reach the recipient within a certain time.
Further information on data transmission can be found under Communication in the information system.
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