After a network scan, other devices besides the system-specific devices have appeared in the topology. Is that due to the open subnet mask?
PROscan® Active was developed to provide a complete overview of all devices existing in the network (not only PROFINET). That is why various mechanisms (e.g. DCP query) are used for searching for active devices in the querying process and these are displayed then. For this reason, devices are also detected that do not have an IP address. A change of the subnet mask therefore does not lead to the desired result for you.
In order to remove the undesired devices from the overview, you need to disconnect the connection to them before the scan. If that is not possible, the "excess" devices can be deleted manually afterwards.