User`s guide

PCIS-DASK Application Hints

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//setting the DMA buffers repeatedly

DI_ContMultiBufferSetup (card, in_buf, data_size, &BufferId);

…

// start multi-buffered DI

DI_ContMultiBufferStart (card, 0, 1);

do {

DI_AsyncDblBufferHalfReady(card, &HalfReady);

} while (!HalfReady);

//Handling the ready data

} while (!clear_op);

DI_AsyncClear(card, &count);

…

Release_Card(card);

5.4 Digital Output Programming Hints

PCIS-DASK provides three kinds of digital output operation  non-buffered

single-point digital output operation, buffered continuous digital output

operation and pattern generation.

The non-buffered single-point DO uses software polling method to write data

to the device. The programming scheme for this kind of DO operation is

described in section 5.4.1.

The buffered continuous DO uses DMA transfer method to transfer data from

user’s buffer to device. The maximum number of count in one transfer depends

on the size of initially allocated memory for digital output in the driver. The

driver allocates the memory at system boot time (in Window NT) or Windows

startup time (in Window 98). We recommend the applications use

DO_InitialMemoryAllocated function to get the size of initially allocated memory

before start performing continuous DO operation.

The buffered continuous digital output includes synchronous continuous DO

and asynchronous continuous DO. They are described in section 5.4.2 and

5.4.3 section individually. About the special consideration and performance

issues for the buffered continuous digital output, please refer to the Continuous

Data Transfer in PCIS-DASK chapter for the details.

The Pattern Generation DO outputs digital data pattern repeatedly at a