fix

src/RegisterDatapoint.py

@@ -169,8 +169,10 @@ class DiscreteInputDatapoint(ReadOnlyDatapoint):
 def checkRegisterList(registers):
     for r in registers:
         if not isinstance(r, AbstractModbusDatapoint):
+            raise ValueError('Entry in register list {0!s} is not derived from class AbstractModbusDatapoint'.format(r))        
+        else:
             r.errorCount = 0
             print("Datapoint loaded: {0!s}".format(r))
-            raise ValueError('Entry in register list {0!s} is not derived from class AbstractModbusDatapoint'.format(r))        
+