I think this “BootUp” has to be considered in the context of the Powerlink-Device and its Connection.
Every time a Powerlink Connection is established a Device will be initialised in the Network. I would asume that the Description “Bootup” will mean this initialisation when the connection will be established.
When you Reboot your PLC the Powerlink-Master will also restart and then this should also go throuh the init phase of the Powerlink Devices. So also a BootUp of the PLC would be included in the context.
But i am not an expert in Powerlink 3rd Party Devices.