Changes made for Pathfinder 5226 controllers.

In a closed loop system the motion of an axis is based on calculated set points of where it should be in real life. If the real life feedback is not matching up with the set point positions then the control will be adjusted with a PID system to try and match the actual position with the set points. Factors like friction, gravity or physical limitations can all cause the closed loop system to adjust the analog accordingly. One problem that can arise from this is if the feedback fails in some way that will make the loop try to adjust to this new bogus error in the set point. One assumption for when an encoder fails is that the reported counts will probably be way different then what they were on the previous iteration.

The implementation then to catch a failing encoder is to halt when there is a change in 100 counts per millisecond. This should catch whatever failure has occurred outside of the loop.