MC_ReadActVel

Description

The MC_ReadActVel function block reads the actual velocity of the axis.

Figure 8-120: MC_ReadActVel

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

Arguments

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

Input

Enable	Description	Requests to read the axis's actual velocity
	Data type	BOOL
	Range	0, 1
	Unit	n/a
	Default	—
Axis	Description	Name of a declared instance of the AXIS_REF library function. For more details, About Axis Name and Number
	Data type	AXIS_REF
	Range	[1,256]
	Unit	n/a
	Default	—

Output

Valid	Description	Indicates the value at the ActualVelocity output is available
	Data type	BOOL
Busy	Description	Indicates this function block is executing
	Data type	BOOL
Error	Description	Indicates an invalid input
	Data type	BOOL
ErrorID	Description	Indicates the error if Error output is set to TRUE. See table in PLCopen Function Block ErrorID Output
	Data type	INT
ActualVelocity	Description	Actual velocity of the axis. Please note that oscillations may be seen due to this being an instant velocity, not an average velocity.
	Unit	User unit/sec
	Data type	LREAL

Example

Structured Text

* MC_ReadActVel ST example *);
Inst_MC_ReadActVel( TRUE, Axis1 ); //Inst_MC_ReadActVel is an instance of MC_ReadActVel function block
			
ActualVel := Inst_MC_ReadActVel.ActualVelocity; // store ActualVelocity output into a user defined variable

Ladder Diagram

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