PVAJT Streaming Motion

Table of Contents

• 🔹 What is PVAJT Motion
• 📜 Sample Code

Stream arrays for precise control over Positions, Velocities, Acceleration, Jerk, and Time deltas directly to the frame buffer. Achieve absolute control over the motion path.

🔹 What is PVAJT Motion

PVAJT motion is a lot more complicated to use because it requires an array of Positions, Velocities, Acceleration, Jerk, and Time deltas. The controller is not responsible for figuring out anything because it streams the arrays straight to the frame buffer. This makes it very flexible and gives users absolute control over the motion path. The controller does not do any interpolation or calculations because everything it needs is calculated beforehand in the PVAJT arrays.

Move PVAJT

Output Example

PVAJT is useful if you must control the acceleration and jerk percent profile throughout motion. The example to the right shows a 50% jerk SCurve trapezoidal move. This move requires 7 elements in each array. One segment for each rising/constant/falling segment of the acceleration profile. The math for PVAJT can be very cumbersome. We recommend you explore all other motion types before trying to implement this method. Note: The Position, Velocity, Acceleration, and Jerk arrays are all direction sensitive meaning you must put a (-) sign on negative numbers.

📜 Sample Code

• C#

        int points     = 3;                            // Specify the total number of streamed points. (Very Important!)
        int emptyCount = 2;                           // E-stop generated if there aren't at least this many points loaded. 
   
        double[] positions     = { 1.0, 0.5, 0.75 };   // Specify the positions that you want to reach. (it can be n number)
        double[] velocities    = { 10.0, 20.0, 40.0 }; // Specify the velocities that you want to use to reach your position.
        double[] accelerations = { 4, 4, 4 };          // Specify the accelerations that you want to use to reach your position.
        double[] jerks         = { 50, 50, 50 };       // Specify the jerks that you want to use in each move.
        double[] times         = { 0.4, 0.2, 0.1 };    // Specify the times in which you want to reach each position. 
   
        axis.MovePVAJT(positions,                      // Specify the positions that you want to reach. (it can be n number)
                    velocities,                        // Specify the velocities that you want to reach. (it can be n number)
                    accelerations,                     // Specify the accelerations that you want to use during every move. 
                    jerks,                             // Specify the jerks that you want to use during every move.
                    times,                             // Specify the times in which you want to reach each position. (velocity and acceleration is calculated by the RMP)
                    points,                            // Specify the total number of streamed points.
                    emptyCount,                        // E-stop generated if there are this number or fewer frames loaded. (Typically for PVAJT motion there are two frames per PVAJT point)
                    false,                             // Specify whether points are kept, or are not kept.
                    true);                             // Specify if this is the last MovePVAJT. (If True, this is the final point. If False, more points expected.)
   
        axis.MotionDoneWait();                         // Wait for motion to be completed.