MC_SetOverride

MC_SetOverride 1:

This function block sets the velocity override factor that is applied to movement commands of the axis. The override factor does not apply to movement in the synchronized motion state (e.g. movement induced by MC_GearIn, MC_GearInPos, ...).

Syntax

Definition:

FUNCTION_BLOCK MC_SetOverride
VAR_IN_OUT
    Axis           : Reference To AXIS_REF;
END_VAR
VAR_INPUT
    Enable         : BOOL;
    VelocityFactor : LREAL;
END_VAR
VAR_OUTPUT
    Enabled        : BOOL;
    Error          : BOOL;
    ErrorId        : UDINT;
END_VAR

MC_SetOverride 2: Inputs

Name

Type

Default

Description

Enable

BOOL

 

Write the velocity override factor continuously while Enable = TRUE.

VelocityFactor

LREAL

1.0

Applies to commanded velocities. Valid range is [0,1]. Use STRING_TO_LREAL('#Ignore') to NOT overwrite the previous value.

MC_SetOverride 3: In/Outputs

Name

Type

Description

Axis

Reference To AXIS_REF

Reference to the axis

MC_SetOverride 4: Outputs

Name

Type

Description

Enabled

BOOL

The commanded override is set.

Error

BOOL

Error occurred within function block.

ErrorId

UDINT

Error identifier

Further information

The MC3 axis supports a velocity override ranging from 0 to 100%, which is normalized to a range of 0 to 1. By default, the velocity override (VelocityFactor) is set to 1, which corresponds to 100%. The MC_SetOverride function block can be used to adjust the velocity override within the permissible range.

The velocity override allows you to adjust the velocity of an axis without changing the commanded dynamics (velocity, acceleration, and deceleration). This does not change the underlying motion curve either.

When using couplings, keep in mind that only the master's override is taken into account.

Note on the migration from NC2 to MC3

NC2 and MC3 support a velocity override ranging from 0 to 100%.
In the NC2, the velocity override is specified as a percentage and is set to 0% by default.
In contrast, in the MC3, the value range is normalized to 0 to 1, and the default value is 1, which corresponds to 100%.

Version information

  • TwinCAT Standard >= v3.1.4026.23.1
  • TF5500 MC3 Base >= v4.0.6