diff --git a/src/preprocess.py b/src/preprocess.py
index 10ff11f..c511546 100644
--- a/src/preprocess.py
+++ b/src/preprocess.py
@@ -19,7 +19,11 @@ class SensorTypeNotFoundException (Exception):
     def __init__(self, sensorType):
         self.sensorType = sensorType
 
-class JustIgnoreMessage (Exception): pass
+class JustIgnoreMessage (Exception):
+    def __init__(self, application, device, message):
+        self.application = application
+        self.device = device
+        self.message = message
 
 class DbOp(object):
     def __init__(self, config):
@@ -122,10 +126,10 @@ def mqttOnMessageCallback(client, userdata, message):
                 }
             case 'LMDS200':
                 if f_port != 2:
-                    raise JustIgnoreMessage()
+                    raise JustIgnoreMessage(application['label'], device_id, f"ignore message for f_port {f_port}")
                 battery = struct.unpack('>H', frame[0:2])[0]
-                distance1 = struct.unpack('>H', frame[2:4])[0]
-                distance2 = struct.unpack('>H', frame[4:6])[0]
+                distance1 = struct.unpack('>H', frame[2:4])[0] * 10
+                distance2 = struct.unpack('>H', frame[4:6])[0] * 10
                 logger.debug(f"{frame=}, {battery=}, {distance1=}, {distance2=}")
 
                 statusText = 'Ok'
@@ -146,8 +150,8 @@ def mqttOnMessageCallback(client, userdata, message):
 
         logger.debug(f"{measurement=}")
         dbh.storeMeasurement(measurement)
-    except JustIgnoreMessage:
-        pass
+    except JustIgnoreMessage as e:
+        logger.info(f"JustIgnoreMessage: {e.application}, {e.device}, {e.message}")
     except SensorTypeNotFoundException as e:
         logger.error(f"application has unknown sensor type {e.sensorType}")
     except ApplicationNotFoundException as e: