Using a button to control timeline

Hello everyone.

I wonder if you have had this issue and found a way around it?

I have an animation that is using animations built-in. I thought this was really easy but then right at the last hurdle, I fell over. 

Basically, I wanted an image to slide along from right to left to build a process flow or a timeline. I got the animation working with a 2-second transition and then the next and so on. What I wanted to do was have a "Next Step" button that would pause the animation and then when the user clicked on the button it would start up again and then pause etc.

The trouble is when I do this, I have tried so many different ways to beat this issue, it always stops a few frames before the intended stop/pause point. It completely ruins the effect and it looks very broken.

Losing the will to live here.

I extended the animation to be 10 seconds worth of reading time before it just carries on that isn't good enough because some people read slower than others.

If anyone can help I would appreciate it so much.

I have attached the source file with the first 2 buttons included so you can see the issue.

Calling all cars on this one.

Thanks

 

Don