Index: trunk/FACT++/src/datalogger.cc
===================================================================
--- trunk/FACT++/src/datalogger.cc	(revision 13295)
+++ trunk/FACT++/src/datalogger.cc	(revision 13296)
@@ -407,8 +407,10 @@
 int DataLogger::Write(const Time&time, const std::string& txt, int qos)
 {
+    ostringstream ss;
+    ss << "datalogger: " << txt;
     if (fNightlyLogFile.is_open())
     {
         MessageImp mimp(fNightlyLogFile);
-        mimp.Write(time, txt, qos);
+        mimp.Write(time, ss.str(), qos);
     }
     else if (shouldBackLog)
@@ -416,8 +418,8 @@
              ostringstream str;
              MessageImp mimp(str);
-             mimp.Write(time, txt, qos);
+             mimp.Write(time, ss.str(), qos);
              backLogBuffer.push_back(str.str());
          }
-    return StateMachineDim::Write(time, txt, qos);
+    return StateMachineDim::Write(time, ss.str(), qos);
 }
 // --------------------------------------------------------------------------