diff --git a/doc/revpimodio2.__init__.html b/doc/revpimodio2.__init__.html
index 2bb8f2b..6441740 100644
--- a/doc/revpimodio2.__init__.html
+++ b/doc/revpimodio2.__init__.html
@@ -33,11 +33,32 @@ Classes</h3>
 Functions</h3>
 <table>
 <tr>
+<td><a style="color:#0000FF" href="#acheck">acheck</a></td>
+<td>Check type of given arguments.</td>
+</tr><tr>
 <td><a style="color:#0000FF" href="#consttostr">consttostr</a></td>
 <td>Gibt <class 'str'> fuer Konstanten zurueck.</td>
 </tr>
 </table>
 <hr /><hr />
+<a NAME="acheck" ID="acheck"></a>
+<h2 style="background-color:#FFFFFF;color:#0000FF">acheck</h2>
+<b>acheck</b>(<i>check_type, **kwargs</i>)
+<p>
+Check type of given arguments.
+</p><p>
+    Use the argument name as keyword and the argument itself as value.
+</p><dl>
+<dt><i>check_type</i></dt>
+<dd>
+Type to check
+</dd><dt><i>kwargs</i></dt>
+<dd>
+Arguments to check
+</dd>
+</dl>
+<div align="right"><a style="color:#0000FF" href="#top">Up</a></div>
+<hr /><hr />
 <a NAME="consttostr" ID="consttostr"></a>
 <h2 style="background-color:#FFFFFF;color:#0000FF">consttostr</h2>
 <b>consttostr</b>(<i>value</i>)
diff --git a/doc/revpimodio2.modio.html b/doc/revpimodio2.modio.html
index 2b6dead..fcca538 100644
--- a/doc/revpimodio2.modio.html
+++ b/doc/revpimodio2.modio.html
@@ -180,6 +180,9 @@ Abweichender Pfad zur piCtory Konfigurationsdatei
 </dd><dt><i>simulator</i></dt>
 <dd>
 Laedt das Modul als Simulator und vertauscht IOs
+</dd><dt><i>debug</i></dt>
+<dd>
+Gibt bei allen Fehlern komplette Meldungen aus
 </dd>
 </dl><a NAME="RevPiModIO.__del__" ID="RevPiModIO.__del__"></a>
 <h3 style="background-color:#FFFFFF;color:#FF0000">
@@ -592,7 +595,7 @@ Static Methods</h3>
 <a NAME="RevPiModIODriver.__init__" ID="RevPiModIODriver.__init__"></a>
 <h3 style="background-color:#FFFFFF;color:#FF0000">
 RevPiModIODriver (Constructor)</h3>
-<b>RevPiModIODriver</b>(<i>virtdev, autorefresh=False, monitoring=False, syncoutputs=True, procimg=None, configrsc=None</i>)
+<b>RevPiModIODriver</b>(<i>virtdev, autorefresh=False, monitoring=False, syncoutputs=True, procimg=None, configrsc=None, debug=False</i>)
 <p>
 Instantiiert die Grundfunktionen.
 </p><p>
@@ -652,7 +655,7 @@ Static Methods</h3>
 <a NAME="RevPiModIOSelected.__init__" ID="RevPiModIOSelected.__init__"></a>
 <h3 style="background-color:#FFFFFF;color:#FF0000">
 RevPiModIOSelected (Constructor)</h3>
-<b>RevPiModIOSelected</b>(<i>deviceselection, autorefresh=False, monitoring=False, syncoutputs=True, procimg=None, configrsc=None, simulator=False</i>)
+<b>RevPiModIOSelected</b>(<i>deviceselection, autorefresh=False, monitoring=False, syncoutputs=True, procimg=None, configrsc=None, simulator=False, debug=False</i>)
 <p>
 Instantiiert nur fuer angegebene Devices die Grundfunktionen.
 </p><p>
diff --git a/doc/revpimodio2.netio.html b/doc/revpimodio2.netio.html
index 9a11e8f..eb4a16a 100644
--- a/doc/revpimodio2.netio.html
+++ b/doc/revpimodio2.netio.html
@@ -423,7 +423,7 @@ Static Methods</h3>
 <a NAME="RevPiNetIO.__init__" ID="RevPiNetIO.__init__"></a>
 <h3 style="background-color:#FFFFFF;color:#FF0000">
 RevPiNetIO (Constructor)</h3>
-<b>RevPiNetIO</b>(<i>address, autorefresh=False, monitoring=False, syncoutputs=True, simulator=False</i>)
+<b>RevPiNetIO</b>(<i>address, autorefresh=False, monitoring=False, syncoutputs=True, simulator=False, debug=False</i>)
 <p>
 Instantiiert die Grundfunktionen.
 </p><dl>
@@ -442,6 +442,9 @@ Aktuell gesetzte Outputs vom Prozessabbild einlesen
 </dd><dt><i>simulator</i></dt>
 <dd>
 Laedt das Modul als Simulator und vertauscht IOs
+</dd><dt><i>debug</i></dt>
+<dd>
+Gibt bei allen Fehlern komplette Meldungen aus
 </dd>
 </dl><a NAME="RevPiNetIO._create_myfh" ID="RevPiNetIO._create_myfh"></a>
 <h3 style="background-color:#FFFFFF;color:#FF0000">
@@ -533,7 +536,7 @@ Static Methods</h3>
 <a NAME="RevPiNetIODriver.__init__" ID="RevPiNetIODriver.__init__"></a>
 <h3 style="background-color:#FFFFFF;color:#FF0000">
 RevPiNetIODriver (Constructor)</h3>
-<b>RevPiNetIODriver</b>(<i>address, virtdev, autorefresh=False, monitoring=False, syncoutputs=True</i>)
+<b>RevPiNetIODriver</b>(<i>address, virtdev, autorefresh=False, monitoring=False, syncoutputs=True, debug=False</i>)
 <p>
 Instantiiert die Grundfunktionen.
 </p><p>
@@ -596,7 +599,7 @@ Static Methods</h3>
 <a NAME="RevPiNetIOSelected.__init__" ID="RevPiNetIOSelected.__init__"></a>
 <h3 style="background-color:#FFFFFF;color:#FF0000">
 RevPiNetIOSelected (Constructor)</h3>
-<b>RevPiNetIOSelected</b>(<i>address, deviceselection, autorefresh=False, monitoring=False, syncoutputs=True, simulator=False</i>)
+<b>RevPiNetIOSelected</b>(<i>address, deviceselection, autorefresh=False, monitoring=False, syncoutputs=True, simulator=False, debug=False</i>)
 <p>
 Instantiiert nur fuer angegebene Devices die Grundfunktionen.
 </p><p>
diff --git a/eric-revpimodio2.api b/eric-revpimodio2.api
index 346f981..98bbf09 100644
--- a/eric-revpimodio2.api
+++ b/eric-revpimodio2.api
@@ -7,6 +7,7 @@ revpimodio2.OFF?7
 revpimodio2.OUT?7
 revpimodio2.RED?7
 revpimodio2.RISING?7
+revpimodio2.acheck?4(check_type, **kwargs)
 revpimodio2.app.App?1(app)
 revpimodio2.consttostr?4(value)
 revpimodio2.device.Connect.A3?7
@@ -173,8 +174,8 @@ revpimodio2.modio.RevPiModIO.simulator?7
 revpimodio2.modio.RevPiModIO.syncoutputs?4(device=None)
 revpimodio2.modio.RevPiModIO.writeprocimg?4(device=None)
 revpimodio2.modio.RevPiModIO?1(autorefresh=False, monitoring=False, syncoutputs=True, procimg=None, configrsc=None, simulator=False, debug=False)
-revpimodio2.modio.RevPiModIODriver?1(virtdev, autorefresh=False, monitoring=False, syncoutputs=True, procimg=None, configrsc=None)
-revpimodio2.modio.RevPiModIOSelected?1(deviceselection, autorefresh=False, monitoring=False, syncoutputs=True, procimg=None, configrsc=None, simulator=False)
+revpimodio2.modio.RevPiModIODriver?1(virtdev, autorefresh=False, monitoring=False, syncoutputs=True, procimg=None, configrsc=None, debug=False)
+revpimodio2.modio.RevPiModIOSelected?1(deviceselection, autorefresh=False, monitoring=False, syncoutputs=True, procimg=None, configrsc=None, simulator=False, debug=False)
 revpimodio2.netio.NetFH._connect?5()
 revpimodio2.netio.NetFH._direct_send?5(send_bytes, recv_count)
 revpimodio2.netio.NetFH.clear_dirtybytes?4(position=None)
@@ -201,9 +202,9 @@ revpimodio2.netio.RevPiNetIO.disconnect?4()
 revpimodio2.netio.RevPiNetIO.get_jconfigrsc?4()
 revpimodio2.netio.RevPiNetIO.net_cleardefaultvalues?4(device=None)
 revpimodio2.netio.RevPiNetIO.net_setdefaultvalues?4(device=None)
-revpimodio2.netio.RevPiNetIO?1(address, autorefresh=False, monitoring=False, syncoutputs=True, simulator=False)
-revpimodio2.netio.RevPiNetIODriver?1(address, virtdev, autorefresh=False, monitoring=False, syncoutputs=True)
-revpimodio2.netio.RevPiNetIOSelected?1(address, deviceselection, autorefresh=False, monitoring=False, syncoutputs=True, simulator=False)
+revpimodio2.netio.RevPiNetIO?1(address, autorefresh=False, monitoring=False, syncoutputs=True, simulator=False, debug=False)
+revpimodio2.netio.RevPiNetIODriver?1(address, virtdev, autorefresh=False, monitoring=False, syncoutputs=True, debug=False)
+revpimodio2.netio.RevPiNetIOSelected?1(address, deviceselection, autorefresh=False, monitoring=False, syncoutputs=True, simulator=False, debug=False)
 revpimodio2.netio._sysdeldirty?8
 revpimodio2.netio._sysexit?8
 revpimodio2.netio._sysflush?8
diff --git a/revpimodio2/__init__.py b/revpimodio2/__init__.py
index 946bf38..8feb06f 100644
--- a/revpimodio2/__init__.py
+++ b/revpimodio2/__init__.py
@@ -38,6 +38,28 @@ MEM = 302
 warnings.simplefilter(action="always")
 
 
+def acheck(check_type, **kwargs):
+    """Check type of given arguments.
+
+    Use the argument name as keyword and the argument itself as value.
+
+    @param check_type Type to check
+    @param kwargs Arguments to check
+
+    """
+    for var_name in kwargs:
+        none_okay = var_name.endswith("_noneok")
+
+        if not (isinstance(kwargs[var_name], check_type) or
+                none_okay and kwargs[var_name] is None):
+
+            msg = "Argument '{0}' must be {1}{2}".format(
+                var_name.rstrip("_noneok"), str(check_type),
+                " or <class 'NoneType'>" if none_okay else ""
+            )
+            raise TypeError(msg)
+
+
 def consttostr(value):
     """Gibt <class 'str'> fuer Konstanten zurueck.
 
diff --git a/revpimodio2/helper.py b/revpimodio2/helper.py
index e6fd9e1..37af3cb 100644
--- a/revpimodio2/helper.py
+++ b/revpimodio2/helper.py
@@ -446,7 +446,7 @@ class ProcimgWriter(Thread):
             RuntimeWarning
         )
         if self._modio._debug and e is not None:
-            warnings.warn(str(e))
+            warnings.warn(str(e), RuntimeWarning)
 
     def get_maxioerrors(self):
         """Gibt die Anzahl der maximal erlaubten Fehler zurueck.
diff --git a/revpimodio2/modio.py b/revpimodio2/modio.py
index 023e5a2..55f589a 100644
--- a/revpimodio2/modio.py
+++ b/revpimodio2/modio.py
@@ -9,6 +9,7 @@ from json import load as jload
 from multiprocessing import cpu_count
 from os import access, F_OK, R_OK
 from queue import Empty
+from revpimodio2 import acheck
 from signal import signal, SIG_DFL, SIGINT, SIGTERM
 from threading import Thread, Event, Lock
 from timeit import default_timer
@@ -45,8 +46,18 @@ class RevPiModIO(object):
         @param procimg Abweichender Pfad zum Prozessabbild
         @param configrsc Abweichender Pfad zur piCtory Konfigurationsdatei
         @param simulator Laedt das Modul als Simulator und vertauscht IOs
+        @param debug Gibt bei allen Fehlern komplette Meldungen aus
 
         """
+        # Parameterprüfung
+        acheck(
+            bool, autorefresh=autorefresh, monitoring=monitoring,
+            syncoutputs=syncoutputs, simulator=simulator, debug=debug
+        )
+        acheck(
+            str, procimg_noneok=procimg, configrsc_noneok=configrsc
+        )
+
         self._autorefresh = autorefresh
         self._configrsc = configrsc
         self._monitoring = monitoring
@@ -336,7 +347,7 @@ class RevPiModIO(object):
             RuntimeWarning
         )
         if self._debug and e is not None:
-            warnings.warn(str(e))
+            warnings.warn(str(e), RuntimeWarning)
 
     def _set_cycletime(self, milliseconds):
         """Setzt Aktualisierungsrate der Prozessabbild-Synchronisierung.
@@ -819,7 +830,7 @@ class RevPiModIO(object):
                 )
             mylist = [dev]
 
-        e = None
+        global_ex = None
         workokay = True
         for dev in mylist:
             if not dev._selfupdate:
@@ -831,7 +842,7 @@ class RevPiModIO(object):
                     self._myfh.seek(dev._slc_outoff.start)
                     self._myfh.write(dev._ba_devdata[dev._slc_out])
                 except IOError as e:
-                    e = e
+                    global_ex = e
                     workokay = False
                 finally:
                     self._myfh_lck.release()
@@ -842,11 +853,11 @@ class RevPiModIO(object):
             try:
                 self._myfh.flush()
             except IOError as e:
-                e = e
+                global_ex = e
                 workokay = False
 
         if not workokay:
-            self._gotioerror("writeprocimg", e)
+            self._gotioerror("writeprocimg", global_ex)
 
         return workokay
 
@@ -875,7 +886,8 @@ class RevPiModIOSelected(RevPiModIO):
 
     def __init__(
             self, deviceselection, autorefresh=False, monitoring=False,
-            syncoutputs=True, procimg=None, configrsc=None, simulator=False):
+            syncoutputs=True, procimg=None, configrsc=None,
+            simulator=False, debug=False):
         """Instantiiert nur fuer angegebene Devices die Grundfunktionen.
 
         Der Parameter deviceselection kann eine einzelne
@@ -887,7 +899,8 @@ class RevPiModIOSelected(RevPiModIO):
 
         """
         super().__init__(
-            autorefresh, monitoring, syncoutputs, procimg, configrsc, simulator
+            autorefresh, monitoring, syncoutputs, procimg, configrsc,
+            simulator, debug
         )
 
         # Device liste erstellen
@@ -941,7 +954,7 @@ class RevPiModIODriver(RevPiModIOSelected):
 
     def __init__(
             self, virtdev, autorefresh=False, monitoring=False,
-            syncoutputs=True, procimg=None, configrsc=None):
+            syncoutputs=True, procimg=None, configrsc=None, debug=False):
         """Instantiiert die Grundfunktionen.
 
         Parameter 'monitoring' und 'simulator' stehen hier nicht zur
@@ -953,7 +966,8 @@ class RevPiModIODriver(RevPiModIOSelected):
         """
         # Parent mit monitoring=False und simulator=True laden
         super().__init__(
-            virtdev, autorefresh, False, syncoutputs, procimg, configrsc, True
+            virtdev, autorefresh, False, syncoutputs, procimg, configrsc,
+            True, debug
         )
 
 
diff --git a/revpimodio2/netio.py b/revpimodio2/netio.py
index 04cdd2b..7ac2dc2 100644
--- a/revpimodio2/netio.py
+++ b/revpimodio2/netio.py
@@ -489,7 +489,7 @@ class RevPiNetIO(_RevPiModIO):
 
     def __init__(
             self, address, autorefresh=False, monitoring=False,
-            syncoutputs=True, simulator=False):
+            syncoutputs=True, simulator=False, debug=False):
         """Instantiiert die Grundfunktionen.
 
         @param address: IP-Adresse <class 'str'> / (IP, Port) <class 'tuple'>
@@ -497,6 +497,7 @@ class RevPiNetIO(_RevPiModIO):
         @param monitoring In- und Outputs werden gelesen, niemals geschrieben
         @param syncoutputs Aktuell gesetzte Outputs vom Prozessabbild einlesen
         @param simulator Laedt das Modul als Simulator und vertauscht IOs
+        @param debug Gibt bei allen Fehlern komplette Meldungen aus
 
         """
         check_ip = compile(
@@ -544,7 +545,8 @@ class RevPiNetIO(_RevPiModIO):
             syncoutputs,
             "{0}:{1}".format(*self._address),
             None,
-            simulator
+            simulator,
+            debug
         )
 
         # Netzwerkfilehandler anlegen
@@ -655,7 +657,7 @@ class RevPiNetIOSelected(RevPiNetIO):
 
     def __init__(
             self, address, deviceselection, autorefresh=False,
-            monitoring=False, syncoutputs=True, simulator=False):
+            monitoring=False, syncoutputs=True, simulator=False, debug=False):
         """Instantiiert nur fuer angegebene Devices die Grundfunktionen.
 
         Der Parameter deviceselection kann eine einzelne
@@ -668,7 +670,7 @@ class RevPiNetIOSelected(RevPiNetIO):
 
         """
         super().__init__(
-            address, autorefresh, monitoring, syncoutputs, simulator
+            address, autorefresh, monitoring, syncoutputs, simulator, debug
         )
 
         # Device liste erstellen
@@ -722,7 +724,7 @@ class RevPiNetIODriver(RevPiNetIOSelected):
 
     def __init__(
             self, address, virtdev, autorefresh=False, monitoring=False,
-            syncoutputs=True):
+            syncoutputs=True, debug=False):
         """Instantiiert die Grundfunktionen.
 
         Parameter 'monitoring' und 'simulator' stehen hier nicht zur
@@ -735,5 +737,5 @@ class RevPiNetIODriver(RevPiNetIOSelected):
         """
         # Parent mit monitoring=False und simulator=True laden
         super().__init__(
-            address, virtdev, autorefresh, False, syncoutputs, True
+            address, virtdev, autorefresh, False, syncoutputs, True, debug
         )