As stated in the LabVIEW Help for the Acquire Trajectory Data VI:
"The Acquire Trajectory Data VI initiates the automatic acquisition of position and velocity data for the selected axes. The data is held in an onboard first-in-first-out (FIFO) buffer until later read back with the Read Trajectory Data VI. You can select which axes to acquire data for and program the time period between samples.
The Acquire and Read Trajectory Data VIs are used to acquire and read back time-sampled position and velocity data for analysis and display...Once started, this data acquisition operates autonomously in the background as a separate task. Motion control operates normally and you can execute other motion VIs simultaneously."
The Help also cautions, "Wait an appropria
te amount of time before attempting to read back the trajectory data. Because host communication, event handling, arc point generation, contour point dispensing, buffered breakpoints, and buffered high-speed capture are a higher priority on the controller than acquiring trajectory data, you may notice irregular time spacing of sampled data when host communications or event notification is heavy. To minimize the chance of irregular data, limit host communication to a minimum while acquiring trajectory data. If you still notice irregular data, increase your time period."
I hope this answers your question. Good luck!
