Networks and communication Networks form the basis of communication in the world of automatisation. Several systems must communicate with each other: PC's with each other, PC's with PLC's (Programmable Logic Controllers), PLC's with local I/O which control a machine or a machine park, PLC's mutually: PLC's to several inputs/outputs which are locally established... Decentralisation has following large advantages: there are less cables that must be drawn and it is easily extendable. Every network has its specific applications and properties. We will explain them one by one: Industrial Ethernet / Ethernet MPI (Multiple Point Interface) Profibus RS232 Hydrocontrol JR RS485 Hydroprobe II Other peripheral units: Siwarex weighers, Miltronix weighers