You are writing to a Value(signalling). That means every time a value is written to that node, the Value change event is triggered and will run. It doesn't matter if you are writing the same value to it over and over again.
You should only write to the Value (signalling) in an case structure where the new value is compared to the old value (kept in feedback node.) and is different. That, or in your event case put the code to run in a case structure that only runs when the values from the left hand nodes OldVal <> NewVal.
With the first way, you only fire the event structure when the value has changed.
With the second, way, the event structure fires on every loop iteration, but the code inside the event case only runs if the values are different.
I'd lean to the first way.
