diff --git a/src/udi/handlers/svej/svej.go b/src/udi/handlers/svej/svej.go
index 986d3c5..af6f19d 100644
--- a/src/udi/handlers/svej/svej.go
+++ b/src/udi/handlers/svej/svej.go
@@ -79,16 +79,18 @@ func New(id string, config config.HandlerConfigT) handler.Handler {
   return t
 }
 
-func extractionHelper(subTopics []string, jPayload interface{}, selector string, jp *jsonpath.Compiled) (string, error) {
+func (self *SingleValueExtractorJsonpathHandler) ExtractionHelper(subTopics []string, jPayload interface{}, selector string, jp *jsonpath.Compiled) (string, error) {
   var res string
   switch selector[:2] {
   case "J:":
+    // extract using jsonpath from payload
     r, e := jp.Lookup(jPayload)
     if e != nil {
       return "", fmt.Errorf("jp.Lookup failed with %s", e)
     }
     res = fmt.Sprint(r)
   case "T:":
+    // T: extract from topic
     i, e := strconv.Atoi(selector[2:])
     if e != nil {
       return "", fmt.Errorf("Atoi failed with %s", e)
@@ -97,7 +99,26 @@ func extractionHelper(subTopics []string, jPayload interface{}, selector string,
       return "", fmt.Errorf("not enough subtopics")
     }
     res = subTopics[i]
+  case "L:":
+    // L: extract from topic and later match against devices table in database
+    i, e := strconv.Atoi(selector[2:])
+    if e != nil {
+      return "", fmt.Errorf("Atoi failed with %s", e)
+    }
+    if i >= len(subTopics) {
+      return "", fmt.Errorf("not enough subtopics")
+    }
+    ext := subTopics[i]
+    lookup, err1b := self.dbh.GetDeviceByLabel(ext)
+    if err1b != nil {
+      log.Printf("ext lookup %s failed: %v", ext, err1b)
+      res = ext
+    } else {
+      log.Printf("ext: %s", lookup)
+      res = ext
+    }
   case "C:":
+    // use constant value
     res = selector[2:]
   default:
     return "", fmt.Errorf("Invalid selector: %s", selector[:2])
@@ -111,14 +132,14 @@ func (self *SingleValueExtractorJsonpathHandler) Handle(message handler.MessageT
     self.Lost("Handler is not marked as ready", nil, message)
     return
   }
-  //log.Printf("Handler SingleValueExtractorJsonpath %d processing %s -> %s", self.Id, message.Topic, message.Payload)
+  log.Printf("Handler SingleValueExtractorJsonpath %d processing %s -> %s", self.Id, message.Topic, message.Payload)
 
   var measurement database.Measurement
   measurement.Time = time.Now()
   measurement.Application = self.application
   
   subTopics := strings.Split(message.Topic, "/")
-  //log.Printf("Subtopics: %s", strings.Join(subTopics, ", "))
+  log.Printf("Subtopics: %s", strings.Join(subTopics, ", "))
   var jPayload interface{}
   err := json.Unmarshal([]byte(message.Payload), &jPayload)
   if err != nil {
@@ -126,17 +147,20 @@ func (self *SingleValueExtractorJsonpathHandler) Handle(message handler.MessageT
     return
   }
 
-  device, err1 := extractionHelper(subTopics, jPayload, self.deviceSelector, self.deviceJsonpath)
+  device, err1 := self.ExtractionHelper(subTopics, jPayload, self.deviceSelector, self.deviceJsonpath)
   if err1 != nil {
     self.Lost("Device extraction failed", err1, message)
     return
   }
-  value, err2 := extractionHelper(subTopics, jPayload, self.valueSelector, self.valueJsonpath)
+  log.Printf("device: %s", device) 
+
+  value, err2 := self.ExtractionHelper(subTopics, jPayload, self.valueSelector, self.valueJsonpath)
   if err2 != nil {
     self.Lost("Value extraction failed", err2, message)
     return
   }
-  unit, err3 := extractionHelper(subTopics, jPayload, self.unitSelector, self.unitJsonpath)
+
+  unit, err3 := self.ExtractionHelper(subTopics, jPayload, self.unitSelector, self.unitJsonpath)
   if err3 != nil {
     self.Lost("Unit extraction failed", err3, message)
     return
@@ -152,7 +176,7 @@ func (self *SingleValueExtractorJsonpathHandler) Handle(message handler.MessageT
   measurement.Values = make(map[string]database.VariableType)
   measurement.Values["Value"] = variable
 
-  //log.Printf("Prepared measurement item: %s", measurement)
+  log.Printf("Prepared measurement item: %s", measurement)
   self.dbh.StoreMeasurement(&measurement)
   self.S()
 }