There is a known limitation of the LabPro interface such that data from the photogate will not display until the experiment ends. As a result, you must not click stop before data collection ends on its own.

If you click Stop during data collection, no photogate state data, and angular and tangential velocity data will be stored.

To collect data with the LabPro, you must allow the data collection to run for the entire specified duration. If you are using the prepared files found at: or the file included with Advanced Physics with Vernier — Mechanics (PHYS-AM), you may want to adjust the data collection to a shorter duration, such as 30 seconds. Choose Experiment > Data Collection and change the value for Length.

This issue does not affect LabQuest interfaces (any model).