When to use encoders?

[Mk.32]

US Digital provides 2 E4P encoders in the kit, info here: http://www.usdigital.com/first
They can attach straight to the gearboxes [CIMple] you got and can be used to find the distance your robot travels and how fast.
The encoder's should come with instructions on how to attach them and wiring diagrams are here: http://www.usdigital.com/products/ca.../ca-mic4-w4-nc
In short the A and B channel go to the digital inputs on the digital side card.
All 3 programming languages have built in support for these encoders, if you specify which one you could get some help with that as well.
They are mainly used to find how far you have driven for Auton but can be used for other things.