Axis Analog Jogging

Learn how to jog an axis with RapidScript.

Warning

This is a sample program to assist in the integration of the RMP motion controller with your application. It may not contain all of the logic and safety features that your application requires. We recommend that you wire an external hardware emergency stop (e-stop) button for safety when using our code sample apps. Doing so will help ensure the safety of you and those around you and will prevent potential injury or damage.

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The sample apps assume that the system (network, axes, I/O) are configured prior to running the code featured in the sample app. See the Configuration page for more information.

Precondition

This sample application requires:
  1. At least one axis (can be a phantom)
  2. At least one analog input

📜 Axis Analog Jogging Sample App
A sample application that jogs an axis based on an exponential moving average of an analog input value.

void main()
{
  // user sets these values
  uint32 axis = 0;
  int32 analogChannel = 0;
  double analogMidrange = 10000.0;
  double analogDeadband = 100;
  double velocityMultiplier = 0.01;
  double alpha = 0.1;
  
 
  // internals
  int32 i = 0;
  int32 counterStart = 0;
  double position = 0.0;
  double averageAnalog = 0;
  double rawAnalogValue = 0.0;
  double scaledAnalogValue = 0.0;
  double targetVelocity = 0;
  
  AxisClearFaults(axis);
  AxisAmpEnableSet(axis,true);
  double acceleration = AxisDefaultAccelerationGet(axis);
  
  counterStart = ControllerSampleCounterGet();
  while(AxisAmpEnableGet(axis)) 
  {
    rawAnalogValue =  AxisAnalogInGet(axis, analogChannel); 
    scaledAnalogValue = rawAnalogValue - analogMidrange;
    
    if( abs(scaledAnalogValue) < analogDeadband)
    {
      scaledAnalogValue = 0.0;
    }
    
    scaledAnalogValue = scaledAnalogValue * velocityMultiplier; // multiplier
    averageAnalog = (alpha * scaledAnalogValue) + (1.0 - alpha) * averageAnalog; // exponential moving average
    targetVelocity = averageAnalog * averageAnalog * averageAnalog; // cubic velocity
    
    AxisMoveVelocity(axis, targetVelocity, acceleration); 
    wait(0.005);  // no need to change velocity faster than every 5ms
    
    //print("analog: " + scaledAnalogValue + " velocity: " + targetVelocity + " loops: " + i);
    ++i;
  }
  print(MethodTiming(counterStart, i) + "ms per loop.  total loops = " + i + " loops.");
}
 
double MethodTiming(int32 start, int32 loops)
{
  int32 end = ControllerSampleCounterGet();
  return (end - start) / loops;
}

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