Broadcast Out-of-Band (UDP) Programming
Several DS commands are intended to be sent as broadcast UDP datagrams (column 'B' in the command table at commands, messages, and replies details which commands are accepted in broadcast packets). For example, the Echo (X) command , when sent as UDP broadcast, makes all locally attached DS send back a reply. This way it is possible to "auto-discover" all Device Servers on the local network segment and also receive their current status.
All other commands, not marked with a '+' in the 'B' column are supposed to address specific DS. When sent in the broadcast mode they are ignored by all Device Servers except the one that has been pre-selected using the Select In Broadcast Mode (W) command . This method provides a way to program the DS with invalid IP-address (address, that is incompatible with the network) when it is not possible to communicate with this DS in a "normal" way (i.e. by sending UDP datagrams to its IP-address). Once a certain DS has been pre-selected commands such as Set Setting (S) sent in the broadcast mode are accepted and processed by this DS as if they were regular non-broadcast datagrams.