Run/Stop Indicator Displays False When Running Motor at Low SpeedsPrimary Software: Driver Software>>NI-Motion/FlexMotionPrimary Software Version: 7.7 Primary Software Fixed Version: N/A Secondary Software: Utility Software>>Measurement & Automation Explorer Hardware: Motion Control>>Controllers>>PCI-7330
Problem: When I run my motor at normal speeds and use the Read per Axis Status VI to view the Run/Stop indicator, it returns true. When I run my motor at low speeds, the indicator returns false. Why doesn't the indicator always work? Solution: The Run/Stop indicator is based on a threshold value settable in Measurement & Automation Explorer. The threshold is defined by the number of steps or counts per trajectory update period which default to 1 and 250 microseconds, respectively. This means that by default the Run/Stop indicator will display True only if the motor is running above 4000 steps or counts per second. To change the threshold speed, follow the instructions below. Set the number of steps or counts within the Trajectory Settings for a given axis as seen below.  Set the update period under Control Loop Settings but realize that this can affect the performance of your motion system by introducing jitter.  While the above method can be used to change the threshold for the Run/Stop indicator, the preferred method for indicating whether an axis is moving is to use the Move Complete indicator. It will show true once the axis has finished a specified move and is not affected by the threshold value. Related Links: KnowledgeBase 38TA8OA2: What is the Minimum Velocity I Can Move My Motors? Attachments:
Report Date: 05/18/2009 Last Updated: 12/07/2009 Document ID: 4XHD6DZY |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
