Program your own Finite State Machine using a SPLat Controller for only $29.00.
The EC1 "EasyOne", a 32-bit fully featured SPLat Controller with USB and true multi-tasking is a easy way to learn and a cheap way to build your project.
State Diagrams 7, Time-outs
Timeouts are a very versatile tool for fault detection in control systems. In a majority of cases where an external response is expected as a result of some output from the controller, a timeout can be effective in detecting a problem.
In Figure 7 I have added an alarm function. Can you work out what it does?
When you have made an honest attempt to work it out, check your thoughts
here: 
(You will learn 10x as much by working it out for yourself)