The moteus controller, when it implements its control algorithms, uses the internal RC oscillator of the onboard STM32G4 microcontroller to calculate things like velocity and to advance position over time. Typically, this is accurate to within 0.5% which is more than sufficient for most applications. However, there are cases where it does matter.

One common case is when multiple moteus controllers are operated together, and either the relative velocities of the controllers must match closely, or the time required to complete long trajectories must match closely. For example, if a trajectory would take 100s to complete, then a 0.5% difference in clock rate between two controllers would result in one completing 0.5s before the other.