question: @ Override protected Sensor createNewSensor ( String systemName , String userName ) { if ( log . isDebugEnabled ( ) ) { log . debug ( "createNewSensor " + systemName + " " + userName ) ; } Sensor s ; String sName = SerialAddress . normalizeSystemName ( systemName ) ; if ( sName . equals ( "" ) ) { log . error ( "Invalid Sensor system name - " + systemName ) ; return null ; } s = getBySystemName ( sName ) ; if ( s != null ) { log . error ( "Sensor with this name already exists - " + systemName ) ; return null ; } String altName = SerialAddress . convertSystemNameToAlternate ( sName ) ; s = getBySystemName ( altName ) ; if ( s != null ) { log . error ( "Sensor with name '" + systemName + "' already exists as '" + altName + "'" ) ; return null ; } int bit = SerialAddress . getBitFromSystemName ( sName ) ; if ( ( bit <= 0 ) || ( bit >= SENSORSPERNODE ) ) { log . error ( "Sensor bit number, " + Integer . toString ( bit ) + ", is outside the supported range, 1-" + Integer . toString ( SENSORSPERNODE - 1 ) ) ; return null ; } if ( userName == null ) { s = new SerialSensor ( sName ) ; } else { s = new SerialSensor ( sName , userName ) ; } SerialNode node = SerialAddress . getNodeFromSystemName ( sName ) ; if ( node == null ) { log . warn ( "Sensor " + sName + " refers to an undefined Serial Node." ) ; return s ; } node . registerSensor ( s , bit ) ; if ( log . isDebugEnabled ( ) ) { log . debug ( "register " + s . getSystemName ( ) + " in node " + node ) ; } return s ; }
target:  Create a new sensor if all checks are passed System name is normalized to ensure uniqueness.