Function BlockMC_AxisSetDefaultsPLCopen motion iconPipe Network motion icon

Description

MC_AxisSetDefaults sets the default kinematic variables for MC_MoveDirAbs and MC_MoveDirRel. These variables are only used with the MC_MoveDir function blocks.

Each axis within the group must have the default kinematic parameters of Velocity, Acceleration, Deceleration, and JerkClosedIn physics, jerk is the rate of change of acceleration; more precisely, the derivative of acceleration with respect to time set to values greater than zero. A non-zero Jerk value will perform an S-Curve rather than a trapezoidal move. Each axis within the group must have these values set before a direct move can be started.


  • Jerk with a non-zero value is currently not supported for coordinated motion. Jerk parameters are currently ignored.

The function block returns an error if the group state is not GroupStandby or GroupDisabled.

Figure 7-171: MC_AxisSetDefaults

Related Functions

MC_MoveDirAbs, MC_MoveDirRel, MC_ErrorDescription

Coordinated Motion, the top-level topic for Coordinated Motion.

See also:

Arguments

Input

Execute Description On the rising edgeClosedA rising edge is the transition of a digital signal from low to high. It is also called positive edge, request to set the default kinematic parameters.
  Data type BOOL
  Range 0, 1
  Unit N/A
  Default
Axis Description Reference to the axis which will have its default kinematic parameters set.
  Data type AXIS_REF
  Range
  Unit N/A
  Default
Velocity Description The default velocity.
  Data type LREAL
  Range

0 < Velocity < ( 20 * Acceleration ) and 0 < Velocity < ( 20 * Deceleration)

See Limitations on Acceleration and Jerk for more information.

  Unit User units per second
  Default
Acceleration Description

Trapezoidal: Acceleration rate
S-curve: Maximum acceleration

see "Selection of Acceleration and Jerk Parameters for Function Blocks"

  Data type LREAL
  Range

( Velocity / 20 ) < Acceleration < ( 2 * Jerk )

See Limitations on Acceleration and Jerk for more information.

  Unit User units per second2
  Default
Deceleration Description

Trapezoidal: Deceleration rate
S-curve: Unused

  Data type LREAL
  Range ( Velocity / 20 ) < Deceleration < ( 2 * Jerk )
  Unit User unit per second2
  Default
Jerk Description

Trapezoidal: 0
S-curve: Constant jerkClosedIn physics, jerk is the rate of change of acceleration; more precisely, the derivative of acceleration with respect to time


  • Currently the Jerk value is ignored for motion. Only trapezoidal motion is supported.

see "Selection of Acceleration and Jerk Parameters for Function Blocks"

  Data type LREAL
  Range ( Velocity / 20 ) < Acceleration < ( 2 * Jerk ) and ( Velocity / 20 ) < Deceleration < ( 2 * Jerk )
  Unit User units per second3
  Default

Output

Done Description

If True, then the command completed successfully.

  Data type BOOL
Error Description If True, then an error has occurred
  Data type BOOL
ErrorID Description Indicates the error if Error output is set to TRUE. See the table in PLCopen Function Block ErrorID Output.
  Data type DINT

Example

Structured Text

 (* STClosed"Structured text"
A high-level language that is block structured and syntactically resembles Pascal MC_AxisSetDefaults Example *)

default_velocity       := 50.0; 
default_acceleration   := 250.0;
default_deceleration   := 300.0;
default_jerk           := 1000.0;

Inst_MC_AxisSetDefaults ( TRUE, CoordAxis1_ref, default_velocity, default_acceleration, default_deceleration, default_jerk);

Instruction List

            BEGIN_ILClosed"Instruction list"
This is a low-level language and resembles assembly
     CAL Inst_MC_AxisSetDefaults( TRUE, CoordAxis1_Ref, default_velocity, default_acceleration, default_deceleration, default_jerk)
END_IL

Function Block Diagram

Ladder Diagram

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