NI-Motion Help

Edition Date: August 2012

Part Number: 372134F-01

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An axis consists of a trajectory generator, PID or stepper control block, and some sort of output resource, either a digital-to-analog converter (DAC) output or a stepper pulse generator output. Servo axes must also have some sort of feedback resource, either an encoder or ADC channel. Closed-loop stepper axes also require a feedback resource, and can use either encoder or ADC inputs. Open-loop stepper axes do not require feedback for correct operation. The following table lists the resource IDs and constants for axes:

Resource Name Resource ID Constant
Axis Control 0 (0x00) NIMC_AXIS_CTRL
Axis 1 1 (0x01) NIMC_AXIS1
Axis 2 2 (0x02) NIMC_AXIS2
Axis 3 3 (0x03) NIMC_AXIS3
Axis 4 4 (0x04) NIMC_AXIS4
Axis 5 5 (0x05) NIMC_AXIS5
Axis 6 6 (0x06) NIMC_AXIS6
Axis 7 7 (0x07) NIMC_AXIS7
Axis 8 8 (0x08) NIMC_AXIS8

Functions that can operate on multiple axes simultaneously, such as Read Blend Status and Start Motion, can take the axis control (NIMC_AXIS_CTRL) as their resource parameter.

Use the appropriate constant value defined in the MotnCnst.h or motncnst.bas file. For example, to use axis 8 with the Configure Axis Resources function, pass NIMC_AXIS8 for the axis parameter:

status = flex_config_axis(u8 boardID, NIMC_AXIS8, u8 primaryFeedback, u8 secondaryFeedback,
                          u8 primaryOutput, u8 secondaryOutput);


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