FAQ

Do I need to call otg() every cycle?

Yes. Struckig is designed for cyclic execution. Skipping calls leads to discontinuous setpoints and poor motion quality.

Should I always use EnableAutoPropagate := TRUE?

For normal online use, yes. It is the default workflow and keeps Current* aligned with generated New* values.

Use manual propagation only when you explicitly need custom stepping behavior.

Why do I get TrajectoryState.Error?

Most errors are input-related:

• invalid values (NaN or negative limits)
• target kinematics outside configured constraints
• zero-limit conflicts in constrained/synchronized cases

Check both ErrorCode() and ErrorMessage().

What is the best synchronization mode?

• TimeSync for shared arrival time
• Phase for coordinated path progression
• None for independent axis timing

There is no universal best mode. Select based on machine behavior.

Why does ValidateInput pass but runtime still fails?

Inputs may change between validation and execution, or external logic may write invalid values later in the cycle. Keep validation and otg() close in deterministic code.

Can I mix control interfaces per axis?

Yes, with PerDofControlInterface. Do this only when required, since mixed-interface trajectories are harder to reason about during maintenance.

Does MinDuration always extend the move?

No. It only affects trajectories that would otherwise finish earlier than the specified minimum.

Why does motion feel rough near limits?

Usually jerk or acceleration is too high for the mechanical system. Reduce MaxJerk first, then reevaluate MaxAcceleration.

Should I use Continuous or Discrete discretization?

For PLC cycle-oriented control, Discrete is often easier to integrate and reason about. Continuous can be useful when strict cycle quantization is not required.