User's Manual

Chapter 2 Function Reference — DIG_Block_Clear
NI-DAQ FRM for PC Compatibles 2-148
© National Instruments Corporation
DIG_Block_Clear
Format
status = DIG_Block_Clear (deviceNumber, group)
Purpose
Halts any ongoing asynchronous transfer, allowing another transfer to be initiated.
Parameters
Input
Parameter Discussion
group is the group involved in the asynchronous transfer.
Range: 1 or 2 for most devices.
1 through 8 for the DIO-96.
Using This Function
(AT-DIO-32F only) If you aligned the buffer that you used in the previous call to
DIG_Block_Out or DIG_Block_In by a call to Align_DMA_Buffer, DIG_Block_Clear
unaligns that buffer before returning. Unaligning a buffer means that the data is shifted so that
the first data point is located at buffer[0].
After NI-DAQ has started a block transfer, you must call
DIG_Block_Clear before NI-DAQ
can initiate another block transfer. Notice that
DIG_Block_Check makes this call for you
when it sees that NI-DAQ has completed a transfer.
DIG_Block_Clear does not change any
current group assignments, alter the current handshaking settings, or affect the state of the
pattern generation mode.
Name Type Description
deviceNumber i16 assigned by configuration utility
group i16 group