Within the framework of Industry 4.0, there is a lot of talk about monitoring for the purpose of preventive maintenance. For example, it can be measuring temperature or vibrations on different machine parts to detect mechanical wear. Yet many forget to monitor the most central aspect of all: the plant's industrial OT network.
Of course, different types of problems can arise in OT networks. Contacts and cabling wear out, and devices age. It is also possible that there were design errors and incorrect component choices from the beginning. In order to detect and prevent this, we must measure the quality of communication. Without measuring, we can only guess what is wrong. In addition, it happens that fully functional components are replaced, because you cannot see where the actual fault lies. It is also important to always measure in connection with new installations and conversions. The PROFINET-INspektor NT from Indu-Sol is a world-leading instrument for analyzing communication quality. Both during conversions and new installations or permanently installed.
Recently we were contacted by a sawmill that was experiencing a lot of disruptions in its PROFINET network. The plant was eight years old and had been experiencing problems since start-up, mostly in the form of alarms that operators had to acknowledge. Relatively minor disruptions but which caused recurring production losses.
The solution to this customer's problem was to rebuild the network to comply with PI standards and reduce the network load, as well as install equipment for permanent monitoring.
Incorrect choice of switches
This relatively large network was built with unmanaged switches, which is completely insane from a troubleshooting point of view. This is because it is impossible to see what the topology looks like. There was also a lack of a clear layout of the network in the electrical documentation. These switches could not handle the load they were subjected to. So the first step was to replace all the switches, a total of eight, with PROmesh switches from Indu-Sol. After this we were able to see the entire topology and got more stable operation.
It turned out that the network was not built in a satisfactory way. There was too much line depth in relation to the update rate of the devices. Devices had also been installed between switches. This is not good as the device switches cannot handle that load. So the entire network was rebuilt to meet the current standard.
Another problem was vibrations. To reduce the impact of this, some connectors were replaced with 90-degree models. This reduced vibrations in the connector section. The suspension of some control panels was also rebuilt to counteract vibrations.
Prevent future downtime
Vi installerade också en PROFINET-INspektor NT i nätverket. Detta ger möjlighet till att förebygga framtida fel genom att man har ständig koll på nätverkskvaliteten. Efter ombyggnaden fungerade nätverket perfekt utan några mätbara störningar. Den permanenta övervakningen som byggdes in kommer också att hjälpa kunden att hitta fel i framtiden.
Are you experiencing problems in your PROFINET networks? Contact us! We have helped many and can help you too.