diff --git a/pypcc/opcuaserv/convert_unit.py b/pypcc/opcuaserv/convert_unit.py
index 877c9481ad3647d155508e62cca6c0678560eab1..2404653ec934b9e5a0deee17d8fd05b75992288e 100644
--- a/pypcc/opcuaserv/convert_unit.py
+++ b/pypcc/opcuaserv/convert_unit.py
@@ -8,6 +8,9 @@ def period2RPM(T):
 def bool_invert(T):
   return not(T);
 
+def bool_invert_inv(T):
+  return not(T);
+
 def temp_check(T):
   if (T<-100) or (T>200): return float('nan')
   return T;
@@ -16,4 +19,4 @@ def int12_to_bool_inv(data):
     return 1 if data else 2
 
 def int12_to_bool(data):
-    return data==1
\ No newline at end of file
+    return data==1