MC_Halt

PLCopen motion icon

Function Block - Decelerates an axis to zero velocity.

Inputs

Input	Data Type	Range	Unit	Default	Description
Execute	BOOL	FALSE, TRUE	N/A	No default	On the rising edge, request to queue the move.
Axis	AXIS_REF	1 to 256	N/A	No default	Name of a declared instance of the AXIS_REF library function. See Axis Name and Number. See AXIS_REF Structure.
Deceleration	LREAL	No range	User unit/sec²	No default	Trapezoidal: Deceleration rate. S-curve: Unused. See S-curve and Trapezoidal Acceleration / Deceleration.
Jerk	LREAL	No range	User unit/sec³	No default	Trapezoidal: 0 (zero). S-curve: Constant jerk. See S-curve and Trapezoidal Acceleration / Deceleration.
BufferMode	SINT	0 to 5	N/A	No default	0 = Abort. 1 = Buffer. 2 = Blend to active. 3 = Blend to next. 4 = Blend to low velocity. 5 = Blend to high velocity. See Buffer Modes.

Outputs

Output	Data Type	Range	Unit	Description
Done	BOOL	FALSE, TRUE	N/A	Indicates the move completed successfully. The Command Position has reached the endpoint.
Busy	BOOL	FALSE, TRUE	N/A	High from the moment the Execute input goes high until the time the move is ended.
Active	BOOL	FALSE, TRUE	N/A	Indicates this move is the Active move.
CommandAborted	BOOL	FALSE, TRUE	N/A	Indicates the move was aborted.
Error	BOOL	FALSE, TRUE	N/A	Indicates either: An invalid input was specified. The move was terminated due to an error.
ErrorID	INT	No range	N/A	Indicates the error if the Error output is set to TRUE. See PLCopen Function Block ErrorIDs.

Remarks

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

See Function Blocks - General Rules about how inputs and outputs work.
It is a queued single-axis move.
- The move is complete when the axis reaches zero velocity.
It is typically used with Abort at the BufferMode input to terminate a move.
See MC_Stop to execute a stop that cannot be aborted.
See Main about how this function is used in the Hole punch project.

Figure 1: MC_Halt

Time Diagram

This example shows the behavior in combination with a MC_MoveVelocity.

A rotating axis is ramped down with FB2 MC_Halt.
Another motion command overrides the MC_Halt command.
- MC_Halt allows this, in contrast to MC_Stop.
The axis can accelerate again without reaching standstill.

Figure 2: Time Diagrams: First and Second FBs

Figure 3: Time Diagram

FBD Language Example

Not available.

FFLD Language Example

IL Language Example

Not available.

ST Language Example

(* MC_Halt ST example *)
Inst_MC_Halt( HaltReq, Axis1,100.0, 100.0, 0 );
//Inst_MC_Halt is an instance of MC_halt function block
HaltComplete := Inst_MC_Halt.Done;              //store Done output into user defined variable