Siemens SIMATIC ET 200SP Manual page 17

Cabling with fixed connection setting
If you set a fixed connection setting of the port in STEP 7, you should also disable
"Autonegotiation/Autocrossover".
You can find more information on this topic in the STEP 7 online help and
● As of STEP 7 V14, in the PROFINET with STEP 7 V14
(http://support.automation.siemens.com/WW/view/en/49948856) function manual
● As of STEP 7 V5.5, in the PROFINET System Description
(http://support.automation.siemens.com/WW/view/en/19292127) system manual
Real-time communication
A transmission method for PROFINET IO based on cyclic data exchange with a provider-
consumer model.
Isochronous real-time communication
Synchronized communication protocol for cyclic exchange of IRT data between PROFINET
devices. A reserved bandwidth is available in the send cycle for IRT data. The reserved
bandwidth ensures that the IRT data can also be transferred with another high network load
(e.g. TCP/IP communication or additional real time communication) at reserved,
chronologically synchronized intervals.
A topological configuration is required for IRT.
Note
IO controller as sync master with IRT communication
We recommend also operating the IO controller as a sync master when configuring the IRT
communication.
Otherwise, IO devices with IRT and RT configuration could fail as a result of sync master
failure.
You can find more information on the configuration of synchronized PROFINET devices in
sync domains in the STEP 7 online help and
● As of STEP 7 V14, in the PROFINET with STEP 7 V14
(http://support.automation.siemens.com/WW/view/en/49948856) function manual
● As of STEP 7 V5.5, in the PROFINET System Description
(http://support.automation.siemens.com/WW/view/en/19292127) system manual
IM 155-6 PN HS interface module (6ES7155-6AU00-0DN0)
Manual, 09/2016, A5E34928647-AA
Product overview
2.2 Functions
17