diff --git a/frappy/mixins.py b/frappy/mixins.py
index d35f09b..c8e56ea 100644
--- a/frappy/mixins.py
+++ b/frappy/mixins.py
@@ -71,8 +71,11 @@ class HasOutputModule:
 
     def initModule(self):
         super().initModule()
-        if self.output_module:
-            self.output_module.register_input(self.name, self.deactivate_control)
+        try:
+            if self.output_module:
+                self.output_module.register_input(self.name, self.deactivate_control)
+        except Exception:
+            self.log.info(f'{self.name} has no output module')
 
     def set_control_active(self, active):
         """to be overridden for switching hw control"""