Hi Kym,
Welcome to the forum 
The documentation for this product is a bit tricky to parse as it can operate in a few different modes.
I think that coin acceptor only has either serial or parallel data output modes.
The video by Sparkfun is probably the best explanation of house it should be used.
I don’t think you will be able to just get a single 5V pulse when it reaches the target threshold. I think section 4.4 Counter Output is describing an active low data pulse.
