EVOLUTION OF A PROFIBUS PROFINETWithin the SIMATIC automation systems have existed various field buses. They have evolved over time into new technologies. For example, buses SINEC L1, L2 or SINEC SINEC H1.
In 1989, in order to allow users to interconnect equipment from different manufacturers Profibus protocol was developed through the work of fifteen companies and institutes, including Siemens company. Profibusprotocol is an evolution of SINEC L2, though unsupported each other. It is not uncommon to find operating IM308B communication modules for the S5-135U, S5-95U communicated with integrated port SINEC L2.
If we study the protocol Profibus according to the ISO / OSI modelfor communications protocols see that in the layer 1, physical layer, uses the standard RS485 . This is a two-wire differential bus is not twisted and shielded.
Profibus today has approximately 20 million nodes installed worldwide, and proved one of the best field buses.
Still, the market demands a step further and thus bringing the PROFINET standard: a bus Ethernet based industrial communication industry.