MC_AxisSetDefaults

PLCopen motion icon Pipe Network motion icon

Function Block A function block groups an algorithm and a set of private data. It has inputs and outputs. - Sets the default kinematic parameters for an axis.

Inputs

Input	Data Type	Range	Unit	Default	Description
Execute	BOOL	0, 1	N/A	No default	On the rising edge A 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.
Axis	AXIS_REF	No range	N/A	No default	Reference to the axis which has its default kinematic parameters set.
Velocity	LREAL	0 < Velocity < (20 * Acceleration) and 0 < Velocity < (20 * Deceleration)	User unit/sec	No default	The default velocity. See Limitations on Acceleration and Jerk for more information.
Acceleration	LREAL	(Velocity / 20) < Acceleration < (2 * Jerk)	User unit/sec²	No default	Trapezoidal: Acceleration rate. S-curve: Maximum acceleration. See S-curve and Trapezoidal Acceleration / Deceleration for more information. See Acceleration and Jerk Parameters for Function Blocks for more information. See Limitations on Acceleration and Jerk for more information.
Deceleration	LREAL	(Velocity / 20) < Deceleration < (2 * Jerk)	User unit/sec²	No default	Trapezoidal: Deceleration rate. S-curve: Unused. See S-curve and Trapezoidal Acceleration / Deceleration for more information.
Jerk	LREAL	(Velocity / 20) < Acceleration < (2 * Jerk) and (Velocity / 20) < Deceleration < (2 * Jerk)	User unit/sec³	No default	Trapezoidal: 0 (zero). S-curve: Constant jerk In 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 S-curve and Trapezoidal Acceleration / Deceleration for more information. See Acceleration and Jerk Parameters for Function Blocks for more information.

Outputs

Output	Data Type	Description
Done	BOOL	If TRUE, the command completed successfully.
Error	BOOL	If TRUE, an error has occurred.
ErrorID	DINT	Indicates the error if Error output is TRUE. See the table in PLCopen Function Block ErrorIDs.

Output

Data Type

Range

Unit

Description

Done

BOOL

If TRUE, the command completed successfully.

Error

BOOL

If TRUE, an error has occurred.

ErrorID

DINT

Indicates the error if Error output is TRUE.

See the table in PLCopen Function Block ErrorIDs.

Remarks

This function block starts a motion-related action and stores data for calculations and error checking.
See Call Function Blocks Multiple Times in the Same Cycle if using a dual-core controller.

See Coordinated Motion, the top-level topic for Coordinated Motion.
The MC_AxisSetDefaults function block sets the default kinematic variables for MC_MoveDirAbs and MC_MoveDirRel.
- These variables are only used with the MC_MoveDir function blocks.
Each axis in the group must have the default kinematic parameters of Velocity, Acceleration, Deceleration, and Jerk set to values greater than 0 (zero).
- A non-zero Jerk value performs an S-Curve instead of a trapezoidal move.
- Each axis in the group must have these values set before a direct move can be started.
The function block returns an error if the group state is not GroupStandby or GroupDisabled.

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

Figure 6-146: MC_AxisSetDefaults

FBD Language Example

FFLD Language Example

IL Language Example

            BEGIN_IL "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

ST Language Example

 (* ST "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);