The core of the LAN-RING system consists of multifunctional L2 industrial switches with a number of exceptional features. In addition to the usual LAN and optical ports, the switches also have digital and alarm inputs, programmable relays, and RS485 serial buses. The switches can thus be used not only for normal data forwarding between LAN and optical ports but also as a certified transmission route of the alarm system, at the same time monitoring switchboard tampers and connected PIR sensors and controlling IP cameras. The switches also support MODBUS RTU and TCP, which makes it very easy to connect sensors from other manufacturers. In conjunction with the PLC IPLOG switches LAN-RING forms a comprehensive system for security and control of even very large objects. METEL also places great emphasis on the long-term reliability of manufactured equipment. All ports, inputs, and outputs are therefore equipped with surge protectors. We are thus able to provide a minimum 5-year warranty on all installations. The switches also support all standard topologies. This means that they can be connected in a point-to-point, star, mesh or circle topology with a reconfiguration time of within 30 ms. A common feature of all LAN-RING switches and PLCs is compatibility with the SIMULand.v4 program and encrypted communication with the SNMPv3 protocol. SIMULand with its graphical interface makes the configuration accessible to a wide range of users. In accordance with the latest requirements, all communication between the SIMULand application and the hardware is encrypted and protected by a hash algorithm against unauthorized changes to the transmitted data.