Performance Considerations

When you configure the DAQmx Acquire step in continuous mode, LabVIEW SignalExpress must sustain a minimum loop rate to ensure the continuity of the acquired data. The loop rate is equal to the number of samples to acquire divided by the sample rate. That is, the software must execute fast enough to acquire the signal continuously without losing any data between each buffer transfer. If you display the acquired data on the data viewer or leave any configuration views open, you can reduce the execution speed of LabVIEW SignalExpress and possibly lose data. If you lose data between buffer transfers, the device returns an overwrite error and breaks the continuity of the acquired data.

If the device returns overwrite errors, you can reduce the sample rate or increase the number of points in the buffer, close any configuration views, remove the acquired signal from the Data View, or de-select the Update Signal Views while Running option in the View menu.

Note  Refer to the NI-DAQmx Help for more information about data acquisition.