Read Velocity in RPM

Usage

status = flex_read_rpm(u8 boardID, u8 axisOrVectorSpace, u8 returnVector);

Purpose

Reads the filtered velocity of an axis or vector space in RPM.

Parameters

Parameter Discussion

axisOrVectorSpace is the axis or vector space to read. Valid values are NIMC_AXIS1 through NIMC_AXIS30 or NIMC_VECTOR_SPACE1 through NIMC_VECTOR_SPACE15. On motion controllers that support fewer than thirty axes, reading non-existent axes or vector spaces returns error –70006 (NIMC_badResourceIDOrAxisError). Refer to Axes and Vector Spaces for axis and vector space resource IDs.

returnVector indicates the destination for the return data generated by this function. Available return vectors include return data to the host (0xFF), to a variable (0x01 through 0x78), to an indirect variable (0x81 through 0xF8), and return no data (0). Refer to Input and Return Vectors for more detailed information.

Note  The suffix _rtn on the function indicates that the data must be returned to the host. When this calling convention is used, no returnVector is required.

Using This Function

This function returns the axis or vector space filtered velocity in RPM. The filtered velocity is measured based on time elapsed between position changes. To avoid quantization error and jitter in the mechanical system, a filtering algorithm in Load Velocity Filter Parameter is performed with parameters configured.

For vector spaces, this function returns vector velocity, the root-mean-square of the filtered velocities of the individual axes that make up the vector space.

Note  This function requires previously loaded values of either counts per revolution (for servo axes) or steps per revolution (for stepper axes) to operate correctly.

Note  Refer to Function Execution Times for benchmark timing information about your controller.