MC_GrpReadActPos

Description

MC_GrpReadActPos fills the array specified by the ‘Position’ argument with the actual position of the system in the coordinate system specified by the CoordSystem argument. This function block does not cause any motion.

Currently, only the ACS coordinate system is supported. See Coordinate Systems to learn more.

Figure 7-165: MC_GrpReadActPos

There is a one to one correspondence between the axes in the Axes Group and the position values in the Position Array. Each element in the Position Array corresponds to the axis element in the Axis Group array. If an index in the Axes Group is unassigned then the position value for that array element in the Position Array will be 0. If the element does contain an axis then the position value will be filled with the current actual position for that axis. Here is an example to illustrate how this works:

This function or function block returns cached data. See Programming a Dual Core Controller for more information.

Related Functions

MC_GrpReadActVel, MC_GrpReadActAcc, MC_GrpReadCmdPos, MC_GrpReadCmdVel

Coordinated Motion, the top-level topic for Coordinated Motion.

Arguments

For more detail on how inputs and outputs work, refer to PLCopen Function Blocks - General Rules.

Input

Enable	Description	If True, then this function block will read the current actual position of the axes in the group
	Data type	BOOL
	Range	0, 1
	Unit	n/a
	Default	—
AxesGroup	Description	The axes group from which the actual position will be read
	Data type	AXES_GROUP_REF
	Range	n/a
	Unit	n/a
	Default	—
CoordSystem	Description	The coordinate system used when reading the actual position
	Data type	SINT
	Range	One of the following enumeration values: MC_COORDINATE_SYSTEM_ACS = 0 MC_COORDINATE_SYSTEM_MCS = 1 MC_COORDINATE_SYSTEM_PCS = 2
	Unit	n/a
	Default	—
Position[]	Description	An array where the position data will be written. The length of the array must equal the maximum number of axes allowed in the group. The maximum number of axes is an argument to the CreateAxesGrp function block that is used to create axes groups.
	Data type	LREAL
	Range	n/a
	Unit	User units
	Default	—

Output

Valid	Description	If true, the positions have been read without error
	Data type	BOOL
Error	Description	If true, an error has occurred.
	Data type	BOOL
ErrorID	Description	Indicates the error if Error output is set to TRUE. See the table PLCopen Function Block ErrorID Output
	Data type	INT

Example

Structured Text

Inst_MC_GrpReadActPos( DoRead, Group, CoordSys, PosList );

IL

BEGIN_IL"Instruction list"
This is a low-level language and resembles assembly
     CAL Inst_MC_GrpReadActPos( DoRead, Group, CoordSys, PosList )
END_IL

FBD

Ladder Diagram

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