Read DAC Output Limit Status Return

Usage

status = flex_read_dac_output_limit_status_rtn(u8 boardID, u16* positiveStatus, u16* negativeStatus);

Purpose

Reads the status of the DAC limits.

Tip  Refer to the Remarks section for information about how the behavior of this function differs between controllers.

Parameters

Parameter Discussion

positiveStatus is a bitmap of the positive DAC torque limit status.

For D1 through D8:
   1 = DAC output at positive limit
   0 = DAC output below positive limit

negativeStatus is a bitmap of the negative DAC torque limit status.

For D1 through D8:
   1 = DAC output at negative limit
   0 = DAC output above negative limit

Using This Function

This function returns the positive and negative torque limit status of the DAC output. Independent DACs that are not mapped to axes do not have torque limits, so those DACs always return False.

A DAC torque limit status is True (1) when the DAC output is saturated at the corresponding limit. This information tells you that the motor is operating at its maximum torque, probably due to an excessively high value of acceleration or deceleration. It also can indicate excessive friction on the axis, a completely stalled motor, or some other system fault.

When an axis is active (not in the killed, motor off state), this function returns the instantaneous state of the torque limit circuits. If the axis trips out on following error (a typical occurrence when operating at the torque limits), the DAC limit status is latched so you can tell which limit, positive or negative, caused the following error trip. The status remains latched until the axis is activated again by a Start Motion, Stop Motion, or Blend Motion function.

Remarks

This section includes information about how the behavior of this function differs among the controllers that support it.

NI SoftMotion Controller Considerations

The following list includes considerations you must make when you are using this function with the NI SoftMotion Controller:

To read the DAC limit status of DACs nine through thirty, use the Read Motion I/O Data function.