OverWrite Mode

Data Type:	int32
Description:	Specifies whether to overwrite samples in the buffer that you have not yet read.

Valid values

DAQmx_Val_OverwriteUnreadSamps	10252	When an acquisition encounters unread data in the buffer, the acquisition continues and overwrites the unread samples with new ones. You can read the new samples by setting RelativeTo to DAQmx_Val_MostRecentSamp and setting Offset to the appropriate number of samples.
DAQmx_Val_DoNotOverwriteUnreadSamps	10159	The acquisition stops when it encounters a sample in the buffer that you have not read.