During startup, the device automatically backs up the configuration data on a KEY-PLUG (as-supplied from the factory) plugged into a SCALANCE W component. Changes to the configuration during operation are also saved on the KEY-PLUG without any additional operator intervention being necessary.

During startup, an unconfigured device automatically loads the configuration data from an inserted KEY-PLUG that has been written to provided the data was written by a compatible device type.

Diagnostics

Incorrect use of the KEY-PLUG, such as inserting a KEY-PLUG containing the configuration of a different device group or general malfunctions of the KEY-PLUG are indicated by diagnostics mechanisms of the host device (LEDs, SNMP, Web based Management, etc.).