diff --git a/AlgebraicDataflowArchitectureModel/src/simulator/Simulator.java b/AlgebraicDataflowArchitectureModel/src/simulator/Simulator.java
index bb90111..6197b03 100644
--- a/AlgebraicDataflowArchitectureModel/src/simulator/Simulator.java
+++ b/AlgebraicDataflowArchitectureModel/src/simulator/Simulator.java
@@ -215,7 +215,7 @@
 
 			@Override
 			public Expression getNextStateValueOf(ResourceIdentifier resId) {
-				if (nextSystemState.getResource(resId).getState() == null) return null;
+				if (nextSystemState.getResource(resId) == null) return null;
 				return nextSystemState.getResource(resId).getState().getValue();
 			}
 		};
@@ -237,6 +237,7 @@
 			for (ResourcePath inResPath: channel.getInputResources()) {
 				if (inResId.isInstanceOf(inResPath)) {
 					// Update the channel state and resource identifiers by the update of the input resource.
+					boolean isInputResourceDepended = false;
 					for (ChannelMember dependedMem: invDependency.keySet()) {
 						if (inResPath == dependedMem.getResource()) {
 							// If some depending resources are to be updated by the update of an depended input resource.
@@ -251,9 +252,16 @@
 								nextChState.addDependingParamAndValue(channelSelValues, paramEnt.getKey(), paramEnt.getValue());								
 							}
 							nextEvents.add(nextEvent);
+							isInputResourceDepended = true;
 						}
 					}
-					if (invDependency.size() == 0) {
+					boolean isInputResourceDepending = false;
+					for (ChannelMember dependingMem: dependency.keySet()) {
+						if (inResPath == dependingMem.getResource()) {
+							isInputResourceDepending = true;
+						}
+					}
+					if (!isInputResourceDepended && !isInputResourceDepending) {
 						Event nextEvent = new Event(channel, inResPath, nextSystemState.getResource(inResId));
 						nextEvent.setMessage(nextEvent.updateDependingParameters(resourceStateValueProvider));
 						nextEvents.add(nextEvent);