Stopping at a relative position

 

The following application example illustrates how, in "Velocity" operating mode, you can control the profile generation such that the movement always stops at the same relative position based on the falling edge at xStart.

Control

Control the axis in the Velocity structure as follows:

  • Set eModuloMode to a modulo travel strategy of MODULO_OFF.
  • Set eStopMode to STOPMODE_RELATIVE.
  • For lrStopPosition, enter the desired relative stop position (in this example: 100 mm).

Interface in the IEC Editor

Trace recording

[1]

SEW_GVL.Interface_Axis2.ProfileGeneration.Velocity.In.xActivate

[2]

SEW_GVL.Interface_Axis2.ProfileGeneration.Velocity.In.xStart

[3]

SEW_GVL_Internal.Axis2._fbProfileGenerationControl._stOUTInterpolation.stSetpointsUserUnits.lrPosition

[4]

SEW_GVL_Internal.Axis2._fbProfileGenerationControl._stOUTInterpolation.stSetpointsUserUnits.lrVelocity

[5]

SEW_GVL_Internal.Axis2._fbProfileGenerationControl._stOUTInterpolation.stSetpointsUserUnits.lrAcceleration

[6]

SEW_GVL.Interface_Axis2.ProfileGeneration.Velocity.Out.xInVelocity

[7]

SEW_GVL.Interface_Axis2.ProfileGeneration.Velocity.Out.xStopped

Note:

The setpoint profile shows that the movement does not stop immediately with the falling edge at xStart. Deceleration is delayed so that the movement stops at the configured position; in this case, it is 100 mm after the falling edge at xStart.