Increase exception handling on init

* Catch DevFail on GetAttNameAll
* Be more verbose

ArchiveExtractor/Access.py

@@ -52,6 +52,7 @@ def init(
         logger.setLevel(getattr(logging, loglevel.upper()))
     except AttributeError:
         logger.error("Wrong log level specified: {}".format(loglevel.upper()))
+        logger.error("Init module failed. You can try to run ArchiveExtractor.init() again with another configuration")
         return
 
     logger.debug("Instanciating extractors device proxy...")
@@ -61,6 +62,7 @@ def init(
             _Extr.append(tango.DeviceProxy(p))
         except tango.DevFailed:
             logger.error("Could not find extractor {}".format(p))
+            logger.error("Init module failed. You can try to run ArchiveExtractor.init() again with another configuration")
             return
 
     logger.debug("{} and {} instanciated.".format(*_Extr))
@@ -70,12 +72,13 @@ def init(
         # set timeout to 3 sec
         e.set_timeout_millis(3000)
 
-    logger.debug("Filling attributes lookup tables...")
+    logger.debug("Filling attributes lookup tables (use GetAttNameAll)...")
     for e in _Extr:
         try:
             _Attr.append(e.getattnameall())
-        except AttributeError:
+        except (tango.DevFailed, AttributeError):
             logger.error("Could not fetch attributes for extractor {}".format(e))
+            logger.error("Init module failed. You can try to run ArchiveExtractor.init() again with another configuration")
             return
 
     logger.debug("HDB: {} TDB: {} attributes counted".format(len(_Attr[0]), len(_Attr[1])))