Profinet

Profinet (usually styled as PROFINET, as a portmanteau for Process Field Network) is an industry technical standard for data communication over Industrial Ethernet, designed for collecting data from, and controlling equipment in industrial systems, with a particular strength in delivering data under tight time constraints. The standard is maintained and supported by Profibus & Profinet International [de], an umbrella organization headquartered in Karlsruhe, Germany.

Profinet implements the interfacing to peripherals. It defines the communication with field connected peripheral devices. Its basis is a cascading real-time concept. Profinet defines the entire data exchange between controllers (called "IO-Controllers") and the devices (called "IO-Devices"), as well as parameter setting and diagnosis. IO-Controllers are typically a PLC, DCS, or IPC; whereas IO-Devices can be varied: I/O blocks, drives, sensors, or actuators. The Profinet protocol is designed for the fast data exchange between Ethernet-based field devices and follows the provider-consumer model. Field devices in a subordinate Profibus line can be integrated in the Profinet system seamlessly via an IO-Proxy (representative of a subordinate bus system).

Applications with Profinet can be divided according to the international standard IEC 61784-2 into four conformance classes:

A Profinet system consists of the following devices:

A minimal Profinet IO-System consists of at least one IO-Controller that controls one or more IO-Devices. In addition, one or more IO-Supervisors can optionally be switched on temporarily for the engineering of the IO-Devices if required.

If two IO-Systems are in the same IP network, the IO-Controllers can also share an input signal as shared input, in which they have read access to the same submodule in an IO-Device. This simplifies the combination of a PLC with a separate safety controller or motion control. Likewise, an entire IO-Device can be shared as a shared device, in which individual submodules of an IO-Device are assigned to different IO-Controllers.

Each automation device with an Ethernet interface can simultaneously fulfill the functionality of an IO-Controller and an IO-Device. If a controller for a partner controller acts as an IO-Device and simultaneously controls its periphery as an IO-Controller, the tasks between controllers can be coordinated without additional devices.

An Application Relation (AR) is established between an IO-Controller and an IO-Device. These ARs are used to define Communication Relations (CR) with different characteristics for the transfer of parameters, cyclic exchange of data and handling of alarms.