MCFB_StepAbsSwitchFastInput

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Function Block - Fast homing to a home switch.

Performs a homing function by searching for an absolute positioned external physical switch.
- The switch must be connected to one of the two fast inputs on the Axis' AKD drive.
An Absolute Switch has two Off (or On) areas.

Usage

The homing is commanded in the most likely direction where the sensor can be found.
If any LimitSwitch is found during Homing (any of them), a special process is started in the opposite direction.
- The AbsSwitch is searched to switch Off (or On, depending on SwitchMode setting).
The Edge (passed by) and homing process is restarted in the original direction and with the same conditions.
- This ensures the end conditions are always the same.

Figure 1: MCFB_StepAbsSwitchFastInput Usage 1

Figure 2: MCFB_StepAbsSwitchFastInput Usage 2

Inputs

Input	Data Type See Data Types.	Range	Unit	Default	Description
Execute	BOOL	FALSE, TRUE	N/A	No default	Request the homing step procedure at the rising edge. Outputs are reset when execute input is FALSE.
AxisID	AXIS_REF	1 to 256	N/A	No default	Structure for specified Axis designated to home. See AXIS_REF Structure.
Direction	BOOL	FALSE, TRUE	N/A	No default	Defines the axis homing direction. 0 (zero) = Clockwise rotation. 1 = Counterclockwise rotation.
SwitchMode	DINT	0 to 3	N/A	No default	Switch state to complete homing. 0 (zero) = Rising edge of sensor. 1 = Falling edge of sensor. 2 = Rising edge when traveling in positive direction but falling edge in negative direction. 3 = Falling edge when traveling in negative direction but rising edge in positive direction.
Velocity	LREAL	No range	User units / sec	No default	Commanded velocity for the homing move.
Acceleration	LREAL	No range	User units / sec²	No default	Commanded acceleration for the homing move.
Deceleration	LREAL	No range	User units / sec²	No default	Commanded deceleration for the homing move.
Jerk	LREAL	No range	User units / sec³	No default	Commanded jerk for the homing move. If 0 (zero), trapezoidal acc/dec is used.
TorqueLimit	LREAL	No range	User units	No default	Maximum torque applied for the homing move. Entered in thousandths of maximum torque. Example: 250 is 250/1000, or 25%.
TimeLimit	TIME	No range	Sec	No default	Maximum time for homing move to complete. If exceeded, the homing procedure errors out. 0 (zero) = no time limit.
DistanceLimit	LREAL	No range	User units	No default	Maximum distance for homing move to complete. If exceeded, the homing procedure errors out. 0 (zero) = no distance limit.
FastInputNum	BOOL	FALSE, TRUE	N/A	No default	0 (zero) = first fast input (X7 pin 10). 1 = second fast input (X7 pin 9).
PosLimitSwitch	BOOL	FALSE, TRUE	N/A	No default	The positive direction limit switch input I/O point.
NegLimitSwitch	BOOL	FALSE, TRUE	N/A	No default	The negative direction limit switch input I/O point.
BufferMode	SINT	Enumerated	N/A	No default	The specified buffer mode. BM_ABORTING BM_BUFFERED BM_BLENDING_PREVIOUS BM_BLENDING_NEXT BM_BLENDING_LOW BM_BLENDING_HIGH See Buffer Modes.

Outputs

Output

Data Type

See Data Types.

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

Set when the function block is active.

CommandAborted

BOOL

FALSE, TRUE

N/A

If TRUE, the command was aborted by another function block.

Error

BOOL

FALSE, TRUE

N/A

Signals an error has occurred within the function block.

ErrorID

INT

Enumerated

N/A

Indicates the error if Error output is TRUE.

Error identifier:

ErrorID	Description
1	TimeLimit exceeded.
2	DistanceLimit exceeded.
3	TorqueLimit exceeded.
4	Axis error stop state.
5	Axis not enabled.
6	Invalid inputs for Velocity-Acceleration-Deceleration.

TriggerPosition

LREAL

No range

User units

FBD Language Example

FFLD Language Example

PosLimitSwitch, NegLimitSwitch are declared I/O points.

IL Language Example

Not available.

ST Language Example

Execute_1 :=1;
(*Positive_Switch and Negitive_Switch are physical hardware in Dictionary. *)

Inst_MC_StepAbsSwitchFastInput( Execute_1, Axis1, 0, 0, 10000.0,Acceleration:=10000.0, 10000.0, 0, 0, 0, 0, 0, Positive_Switch , Negitive_Switch ,  0)

HomeComplete := Inst_MC_StepAbsSwitchFastInput.Done;
HomeBusy := Inst_MC_StepAbsSwitchFastInput.Busy;
HomeActive := Inst_MC_StepAbsSwitchFastInput.Active;
HomeAborted := Inst_MC_StepAbsSwitchFastInput.CommandAborted;
HomeError := Inst_MC_StepAbsSwitchFastInput.Error;
HomeErrorID := Inst_MC_StepAbsSwitchFastInput.ErrorID;
HomeTriggerPosition := Inst_MC_StepAbsSwitchFastInput.TriggerPosition;