Does the M340 Can-Open master detects the presence of the devices which are not configured?

The answer is yes:
This behavior is part of the bootup procedure specified in the standard "CiA302".
At the end of the bootup procedure, after all expected slaves have got their configuration data, a "start all nodes" command is sent by the master.
So each devices connected to the network are identified.

Released for: Schneider Electric Canada