MC_ReadActualVelocity (motion control read actual velocity)

The MC_ReadActualVelocity instruction returns the value of the actual velocity of the feedback axis.

MC_ReadActualVelocity is only applicable to feedback motion.

Before executing MC_ReadActualVelocity, verify that the axis is in one of the following axis states:

Standstill

Discrete Motion

Error Stop

Languages supported: Function block diagram, ladder diagram, structured text.

This instruction applies to the L50E and L70E controllers that support motion control.

MC_ReadActualVelocity parameters
Parameter	Parameter Type	Data Type	Description
AxisIn	Input	FB_AXIS_REF	For an FB_Axis (feedback axis), use the FB_AXIS_REF data type to define AxisIn.
Enable	Input	BOOL	TRUE: Get the value for the actual velocity continuously. FALSE: The data is no longer valid, all outputs are reset to 0, Valid is set to False.
Axis	Output	FB_AXIS_REF	Axis output is read-only in ladder diagram programs. The Axis output parameters are defined in the FB_AXIS_REF data type.
Valid	Output	BOOL	TRUE: The function block is active and new output values are expected. FALSE: The function is not expecting new output values.
Busy	Output	BOOL	TRUE: The function block is not finished. FALSE: The function is idle.
Error	Output	BOOL	Indicates an error occurred. TRUE: An error is detected. FALSE: No error.
ErrorID	Output	UNIT	A unique numeric that identifies the error. The errors for this instruction are defined in Motion control function block error IDs.
ActualVelocity	Output	REAL	The value of the actual velocity for the feedback motion axis (in axis' unit [u/s]). ActualVelocity is a signed value, which includes direction information.

MC_ReadActualVelocity examples

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