Dynamic Adaptation with MC_SetOverride

The dynamics (velocity, acceleration, and jerk) of the active and future movements can be adapted by using MC_SetOverride. An adaptation of the dynamics always means a reduction as compared to the originally commanded movement (factors greater than 1 are not permitted). This allows machine operators to temporarily stop a movement (VelFactor = 0) or execute it with reduced dynamic values, for example to check new movement sequences.

The adaptation of the dynamics with MC_SetOverride and the resulting adaptation of the trajectory take effect directly in the same cycle. The requirement for this is that MC_SetOverride is called before the active movement function block.

For more information, see also the example Velocity Override for SoftMotion Axes.

Supported function blocks

Function Block	Support: `MC_SetOverride`	Comment
`MC_Stop`	--	`MC_Stop` is an emergency stop which should always be executed as quickly as possible. Therefore, the dynamic factors of `MC_SetOverride` do not have any effect on the movement.
`MC_Halt`	✓	The velocity factor has no effect.
`MC_MoveAbsolute` `MC_MoveRelative`	✓
`MC_MoveAdditive`	✓
`MC_MoveSuperimposed`	✓
`MC_MoveVelocity`	✓
`SMC_MoveContinuousAbsolute` `SMC_MoveContinuousRelative`	✓
`MC_Jog` `SMC_Inch`	✓
`SMC_Homing`	✓
`SMC_ControlAxisByPos` `SMC_ControlAxisByPosVel` `SMC_ControlAxisByVel`	O	The dynamic factors have an effect only if the `bAvoidGaps` function is activated and a jump has been detected. The factors of `MC_SetOverride` take into account both the stop and the subsequent absolute movement to close the gap.
`MC_Home`	--	The homing is executed independently by the drive so that the dynamic factors of `MC_SetOverride` have no effect.
`MC_PositionProfile` `MC_VelocityProfile` `MC_AccelerationProfile`	--	We recommend using `MC_CamIn` instead of these function blocks.
`MC_CamIn`	O	The dynamic factors no longer have an effect as soon as the movement is synchronized (`MC_CamIn.InSync = TRUE`).
`MC_CamOut`	--	`MC_CamOut` does not have adjustable dynamic limits and should maintain the current velocity. The dynamic factors of `MC_SetOverride` therefore do not have an effect.
`MC_GearIn`	O	The dynamic factors no longer have an effect as soon as the movement is synchronized (`MC_GearIn.InGear = TRUE`). During ramping, only the acceleration and jerk factors are considered. Changes to the velocity factor (especially `VelFactor=0`) are ignored.
`MC_GearInPos`	--	In contrast to `MC_GearIn`, it does not have a configurable ramping movement. Therefore, the dynamic factors of `MC_SetOverride` do not have an effect.
`SMC_FollowPosition` `SMC_FollowVelocity` `SMC_FollowPositionVelocity` `SMC_FollowSetValues`	--	These function blocks write the set values of the axis (for example, `fSetPosition`). These values should not be modified. Therefore, the dynamic factors of `MC_SetOverride` do not have an effect.
`MC_Phasing`	O	The dynamic factors no longer have an effect as soon as the movement is synchronized (`MC_Phasing.Done = TRUE`). During ramping, only the acceleration and jerk factors are considered. Changes to the velocity factor (especially `VelFactor=0`) are ignored.
`SMC_BacklashCompensation`	--	The dynamic factors do not have an effect on synchronized movements. Therefore, this function block ignores the dynamic factors of `MC_SetOverride`.

Exceeding the target position or target velocity by changing the dynamic factors

Important

If the acceleration factor and/or the jerk factor is reduced during an active movement, then the target position or target velocity may be temporarily exceeded. This can lead to damage to the machine.

With SMC_MoveContinuousAbsolute and SMC_MoveContinuousRelative, a change of the velocity factor can also lead to the limits being exceeded or to a reversal. More details can be found in the documentation of the two function blocks.

Effect of the velocity profile on the use of MC_SetOverride

It is generally recommended to use MC_SetOverride together with a trapezoidal or quadratic velocity profile of the axes. Quadratic-smoothed and sin² velocity profiles do not respond well to restarting or interrupting the movement in certain cases (see Interruption of Movements). Because a change to the override is equivalent to a restart of the movement with changed limits, it is also possible for the commanded limits to be exceeded when using these velocity profiles in combination with MC_SetOverride.

Effect of MC_SetOverride on coordinated movements with an axis group

Coordinated movements with an axis group (for example, MC_MoveLinearAbsolute) consider the overrides set with MC_SetOverride for each axis during movement planning. Conversely, MC_GroupSetOverride overwrites the overrides of each axis of the axis group.