Absolute Motion

Table of Contents

• 🔹 What is Absolute Motion?
• 🔹 Why use Absolute Motion?
• 📜 Sample Code

Use Absolute Motion to move directly to a specified position, ensuring the axis reaches a defined destination regardless of its previous position.

🔹 What is Absolute Motion?

An absolute motion always moves to a specified position without being affected by the previous motion.

🔹 Why use Absolute Motion?

Absolute Motion makes it very easy for us to reach a specified destination.

Note

An Absolute move will move the axis to position 25 rather than 25 units ahead of the current position.
A Relative move will move the axis 25 units ahead of the current position, rather than to position 25.

In our API an absolute motion will let us move a single axis with a trapezoidal profile to an absolute distance.

Note

You can change the velocity, acceleration, and deceleration of a moveSCurve that is executing on the fly simply by calling the function again with different parameters.

📜 Sample Code

• C#

    public const double POSITION     = 2;   // Specify the position to travel to.
    public const double VELOCITY     = 200; // Specify your velocity.     - units: UserUnits/Sec    
    public const double ACCELERATION = 100; // Specify your acceleration. - units: UserUnits/Sec^2
    public const double DECELERATION = 100; // Specify your deceleration. - units: UserUnits/Sec^2
    public const double JERK_PERCENT = 50;  // Specify your jerk percent (0.0 to 100.0)

        axis.MoveTrapezoidal(Constants.POSITION, Constants.VELOCITY, Constants.ACCELERATION, Constants.DECELERATION);// Command simple trapezoidal motion.
        axis.MotionDoneWait();// Wait for motion to be done

• C++

    // *NOTICE* The following constants must be configured before attempting to run with hardware.
    const int NUM_AXES = 1; // The number of axes to configure
    const int AXIS_INDEX = 0; // The index of the axis to configure
   
    // Motion Parameters
    const double POSITION_0 = 0;       
    const double POSITION_1 = 0.5;     
    const double VELOCITY = 1;         
    const double ACCELERATION = 10;    
    const double DECELERATION = 10;    
    const double JERK_PERCENT = 50;    
    const double FINAL_VELOCITY = 0.5; 

      std::cout << "Absolute (Trapezoidal) Motion:" << std::endl;
      std::cout << "Moving to position: " << POSITION_1 << std::endl;
      axis->MoveTrapezoidal(POSITION_1, VELOCITY, ACCELERATION, DECELERATION);
      axis->MotionDoneWait(TIMEOUT);
      std::cout << "Motion Complete" << std::endl;
   
      std::cout << "Moving back to position: " << POSITION_0 << std::endl;
      axis->MoveTrapezoidal(POSITION_0, VELOCITY, ACCELERATION, DECELERATION);
      axis->MotionDoneWait(TIMEOUT);
      std::cout << "Motion Complete\n" << std::endl;