MC_WaitForStableActualPosition

This function block waits for a stable actual position. The command is always buffered and may only be triggered when the previous command ends with zero dynamics.

Syntax

Definition:

FUNCTION_BLOCK MC_WaitForStableActualPosition
VAR_IN_OUT
    Axis              : Reference To  AXIS_REF;
END_VAR
VAR_INPUT
    Execute           : BOOL;
    PositionTolerance : LREAL;
    WaitDuration      : LREAL;
    TimeoutDuration   : LREAL;
END_VAR
VAR_OUTPUT
    InPositionWindow  : BOOL;
    Done              : BOOL;
    Busy              : BOOL;
    Active            : BOOL;
    CommandAborted    : BOOL;
    Error             : BOOL;
    ErrorId           : UDINT;
END_VAR

Inputs

Name	Type	Default	Description
Execute	BOOL		Trigger the command with rising edge.
PositionTolerance	LREAL	#Invalid	Position tolerance around the set position ([PosUnit], positive). The actual position must remain within this window for the command to succeed.
WaitDuration	LREAL	#Invalid	Duration (in seconds) that the actual position needs to consecutively stay inside the position window. Must have a value >= 0.
TimeoutDuration	LREAL	#Ignore	Duration (in seconds) after which an error is triggered if the actual position is not inside the position window. It can be left as 'Ignore' if no timeout is desired, otherwise must have a value > WaitDuration.

In/Outputs

Name	Type	Description
Axis	Reference To AXIS_REF	Reference to the axis

Outputs

Name	Type	Description
InPositionWindow	BOOL	Actual position is currently inside the position window.
Done	BOOL	Actual position has been consecutively inside the position window for at least WaitDuration.
Busy	BOOL	Function block is not finished and new output values are to be expected.
Active	BOOL	Function block has active control on the axis. While Active is TRUE, the set position remains on the final position of the previous command and the set dynamics remain zero.
CommandAborted	BOOL	Command is aborted by another command.
Error	BOOL	Error occurred within function block.
ErrorId	UDINT	Error identifier

Possible error codes

For this function block, the following values, among others, are possible for the ErrorId output:

Error(Hex)	Error(Dec)	Error type	Description
0x8145	33093	Function Block	Mapping of cyclic interface between NC and PLC is missing (e.g., AXIS_REF, AXES_GROUP_REF, ...). A reference used by the function block (e.g., to an axis, group, mover or other motion object) is not linked to the corresponding NC object, or its cyclic mapping is incomplete.
0x8151	33105	State	Command is not allowed in current axis state. If the axis has no controller enable, is in error or has been added to a group, some commands are not permitted.
0x8196	33174	Initialization	Invalid position or distance. The actual or specified position or distance could not be determined or is invalid.
0x81b7	33207	Function Block	The specified time or duration is invalid.

An overview of all NC error codes can be found here:

Other errors

Version information

TwinCAT Standard >= v3.1.4026.23.1
TF5500 MC3 Base >= v4.0.6