PROFINET® Designations

PROFINET® CBA / PROFINET IO

PROFINET contains 2 different solutions:

  • PROFINET® IO
  • PROFINET® CBA (Component Based Automation)

PROFINET® IO is used for communication with decentral periphery like IOs, drives, etc.

PROFINET® CBA is a communication solution for autonomously acting partial units of machines or plants.

PROFINET® IO and PROFINET CBA are using different kind of communications variations of PROFINET:

  • PROFINET® NRT (non-real-time)
  • PROFINET® RT (real-time)
  • PROFINET® IRT (isochronous real-time)
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PROFINET CBA / PROFINET IO

PROFINET® NRT

PROFINET® NRT is used by PROFINET® CBA and PROFINET® IO for the exchange of non-critical data by using standard TCP/IP and UDP/IP transfer mechanism according to IEE 802.3.

PROFINET® RT

PROFINET® IO on RT is the real-time communication for time-critical process data between PLC and decentral periphery like I/O-devices, drives etc.

To reach the real-time behaviour, PROFINET® RT does not use the addressing features and control mechanisms of TCP and UDP. PROFINET® RT is using a separate real-time channel for transmission with a reduced overhead. If used for communication between different networks, the “RT over UDP” mode is available.

PROFINET® IO based on RT can be used in separate and existing networks. The PROFINET® communication runs in parallel to TCP/IP and TCP/UDP communication.

PROFINET® IRT

PROFINET® IRT is used for extremely time-critical applications (e. g. motion control). It uses hardware-aided real-time communication. To use PROFINET® IRT, special hardware with cycle synchronisation is necessary.

Note

Real-time behaviour means that a process has to be executed in a predefined time. The duration of this predefined time interval does not matter; it is only necessary that the process is done during this time. Due to this predictability of this process it is possible (with aid of additional synchronisation methods) to cause chronologically adapted processes.