I am not sure what you mean. Event dispatchers must be called from somewhere else. The one you see in Blueprint editor is there only to specify its signature (what are its input pins - like an interface function).
The actual logic must be given somewhere else.
Take a look at the Bluepritn communications sample and this:
https://docs.unrealengine.com/latest/INT/Engine/Blueprints/UserGuide/EventDispatcher/index.html
Now I have posted a blueprint whcih uses dispatchers in the follwing Thread. Scroll downn a bit and you will see my answer with several blueprints. It shows how a Dispatcher is being called.:
So the general process is:
- Define a dispatcher and specify what its input pins are. (this is what you have done at the moment). You cannot add any logic here.
- You must bind a function (event) to the dispatcher somehwere (usually in another blueprint). YOu can bind multiple functions to a dispatcher. When the dispatcher is called, all those functions will be called. NOTE: The functions being bound must have the exact same signature as the dispatcher itself.
- Call the dispatcher. This is to trigger the execution of the bound functions. Think of it like a notification that something has happened. All functions bound to this dispatcher will be called here with the parameters being passed into the dispatcher call.