User`s manual

Application Hints 61

PCIS-DASK

Digital Input Programming Hints

Double-buffered Asynchronous Continuous Digital Input

This section describes the function flow typical of double-buffered

asynchronous digital input operation. While performing continuous

DI operation, the DI configuration function has to be called at the

beginning of the application. For asynchronous DI, the SyncMode

argument in continuous DI functions has to be set to

ASYNCH_OP. In addition, double-buffered DI operation is

enabled by setting Enable argument of DI_AsyncDblBufferMode

function to 1. For more information on double buffer mode, refer to

section 5.2.

DI_XXXX_Config

(XXXX = card type)

DIAsyncDblBufferMode

With ENABLE = True

Next half buffer

ready for transfer?

YES

DI_ContReadPort/

DI_ContReadPortToFile

With SyncMode = SYNCH_OP

DI_AsyncDblBufferHalfReady

YES

Stop the operation?

YES

AsyncDblBufferTransfer

DI_AsyncClear