PROFINET IO with IRT (Isochronous Real Time)
Isochronous real time: Real time property of PROFINET IO where IRT telegrams are
transferred deterministically via planned communication paths in a defined sequence to
achieve the best possible synchronism and performance between the IO controller and IO
device (drive unit). IRT is also known as time-scheduled communication whereby knowledge
about the network structure (topology) is utilized. IRT requires special network components
that support planned data transfer.
SINAMICS cycle times of minimum 250 μs (onboard) / 500 μs (CBE20) and a jitter accuracy
of less than 1 μs can be achieved when this transmission method is implemented.
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Figure A-20 Bandwidth distribution/reservation, PROFINET IO
Addresses
MAC address
Every Ethernet and therefore every PROFINET interface is assigned a worldwide unique
device identifier in the factory. This 6-byte long device identifier is the MAC address. The MAC
address is divided up as follows:
● Three bytes for the manufacturer's ID
● Three bytes for the device identifier (consecutive number)
The MAC address is on a label of the CBE20 or on the rating plate of the CU320‑2 PN, e.g.:
08-00-06-6B-80-C0.
The Control Unit CU320-2 PN has 2 onboard interfaces:
● One Ethernet interface
● One PROFINET interface with two ports
The MAC addresses of the Ethernet and PROFINET interfaces are stamped on the type plate.
Communication
A.1 Communication
Industrial Security
Configuration Manual, 08/2017, A5E36912609A
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