Let xpresso and python work with custom user data, so we aren't relying on any time node, only our own values. By doing this we can increase or decrease the clock. Two range mappers form the user data will drive two different value, to minimize keyframes and optimize the workflow when animating.
This tutorial is also written:
It's a good way to work with: xpresso, python and user data in one scene to get some hands-on.