MCFB_StepLimitSwitchFastInput

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Function Block A function block groups an algorithm and a set of private data. It has inputs and outputs. - Fast homing to a limit switch.

Inputs

Input	Data Type	Range	Unit	Default	Description
Execute	BOOL	0, 1	N/A	No default	Request the homing step procedure at the rising edge A rising edge is the transition of a digital signal from low to high. It is also called positive edge. Outputs are reset when execute input is FALSE.
AxisID	AXIS_REF	1, 256	N/A	No default	Structure for specified Axis designated to home. See AXIS_REF Structure for more information.
Direction	BOOL	0, 1	N/A	No default	Defines the axis homing direction. 0 (zero) = Clockwise rotation. 1 = Counterclockwise rotation.
LimitSwitchMode	DINT	0, 1	N/A	No default	Limit switch state to complete homing. 0 (zero) = Rising edge of sensor A sensor is a type of transducer that converts one type of energy into another for various purposes including measurement or information transfer. 1 = Falling edge of sensor.
Velocity	LREAL	No range	User unit/sec	No default	Commanded velocity for the homing move.
Acceleration	LREAL	No range	User unit/sec²	No default	Commanded acceleration for the homing move.
Deceleration	LREAL	No range	User unit/sec²	No default	Commanded deceleration for the homing move.
Jerk In physics, jerk is the rate of change of acceleration; more precisely, the derivative of acceleration with respect to time	LREAL	No range	User unit/sec³	No default	Commanded jerk In physics, jerk is the rate of change of acceleration; more precisely, the derivative of acceleration with respect to time for the homing move. If 0 (zero), trapezoidal acc/dec is used.
TorqueLimit	LREAL	No range	User units	No default	Maximum torque Torque is the tendency of a force to rotate an object about an axis. Just as a force is a push or a pull, a torque can be thought of as a twist 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	0, 1	N/A	No default	0 (zero) = first fast input The inputs are taken into account at each cycle depending on the system periodicity (for example each millisecond). Under certain circumstances this can be insufficient when more accuracy is needed, or if a quick response is required from the system. To fill the gap, a drive may have some Fast Input connections (generally one or two). When an event happens that triggers a Fast Input (e.g. when a sensor sends a rising edge), the detection of a signal occurs faster (which can be 1000 times more accurate than the system periodicity). Then the timestamp associated with this input can be provided to the IPC to take corrective action (X7 pin 10). 1 = second fast input (X7 pin 9).
BufferMode	SINT	0, 5	N/A	No default	Define the homing move start action. 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 for more information.

Outputs

Output

Data Type

Range

Unit

Description

Done

BOOL

N/A

Indicates the move completed successfully.
The Command Position has reached the endpoint.

Busy

BOOL

N/A

High from the moment the Execute input goes high until the time the move is ended.

Active

BOOL

N/A

Set when the function block is active.

CommandAborted

BOOL

N/A

Indicates the move was aborted.

Error

BOOL

N/A

Signals an error has occurred within the function block.

ErrorID

INT

N/A

Indicates the error if the Error output is set to 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.

Remarks

Performs a homing function by searching for an external physical switch.
The switch must be connected to one of the two fast inputs The inputs are taken into account at each cycle depending on the system periodicity (for example each millisecond). Under certain circumstances this can be insufficient when more accuracy is needed, or if a quick response is required from the system. To fill the gap, a drive may have some Fast Input connections (generally one or two). When an event happens that triggers a Fast Input (e.g. when a sensor sends a rising edge), the detection of a signal occurs faster (which can be 1000 times more accurate than the system periodicity). Then the timestamp associated with this input can be provided to the IPC to take corrective action on the Axis' AKD drive.
The Axis moves and, when a fast input is triggered, the triggered axis then performs an absolute move to the latched position.

This image shows the function or function block I/O.

Figure 6-97: MCFB_StepLimitSwitchFastInput

Usage

The homing is commanded in the most likely direction where the sensor can be found.

In this example (-).

FBD Language Example

FFLD Language Example

IL Language Example

Not available.

ST Language Example

Execute_1 :=1;

Inst_MCFB_StepLimitSwitchFastInput( Execute_1, Axis1, 0, 0, 10000.0, 10000.0, 10000.0, 0, 0, 0, 0, 0, 0);

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