Profibus is a smart fieldbus technology. It is specifically designed for high-speed serial I/O in factory and building automation applications. It is recognized as the fastest fieldbus in operation. Profibus is an open-standard fieldbus defined by German DIN 19245 Parts 1 & 2. Devices on the system connect to a central line. Once connected, these devices can communicate in an efficient manner, but can go beyond automation messages to participate in self-diagnosis and connection diagnosis.
The data link layer is defined in Profibus as the Fieldbus data link layer (FDL). It is based on a token/bus/floating master system. Profibus is a network made up of two types of devices connected to the bus: master devices and slave devices. It is a bidirectional network, meaning one device (the master) sends a request to a slave, and the slave responds to that request. The bus contention is not a problem because only one master can control the bus at any time, and a slave device must respond immediately to a request from a master. Profibus can support addresses from 0-127, only 0-125 are used, because 126-127 have special uses and are not assigned to operational devices.
Copyright: Cybersecurity & Infrastructure Security Agency (CISA)