Webinar_Question wrote: ↑23 Jul 2024, 11:08
Do we really need managed switches in PN networks?
If so, what is the technical reason behind it?
First, you don't need a managed switch. This is a question of the maintainability and diagnostics of the overall system as well as the simplicity of troubleshooting during system downtimes. Of course, it is an advantage if the machine can diagnose "itself" and, in the event of a fault, I can directly create a comparison between the configured and current topology with the help of the topology from a single tool, such as Proneta. System expansions or new components are also directly visible in this way. There are system operators who deliberately want to do without this convenience. From the PROFINET communication point of view, there is no disadvantage whether the switch has a management system or not.
Certain things must be supported by the network infrastructure. Full duplex is necessary in any case. Also the feature of QoS, defined in IEEE 802.1q with at least 2 prio classes. And the option of blocking IEEE 802.1ab frames.
Different link speeds and their transitions must be considered and the expected network load must be planned accordingly. Tools such as Sinetplan or the PI planning guidelines can help here
https://de.profibus.com/downloads/profi ... uidelines/
Network infrastructure devices that have been designed by the manufacturer for PROFINET communication can also be viewed in the PI Product Finder
https://www.profibus.com/products/product-finder/
If you want to design a network component for PROFINET, the specification (IEC61784-2-3) also contains requirements. Chapter 4.3.4 describes the requirements in detail.
Of course, you can also use devices that provide less power than described in IEC61784-2-3. The statements apply to a defined quantity structure. If my system is smaller or I can reduce the update times (e.g. with WiFi), then I can also use devices with less buffer memory.