National Instruments 321645c-01 用户手册

Chapter 2

Function Reference — WFM_Load

NI-DAQ FRM for PC Compatibles

2-428

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and the pattern of waveform followed by delay followed by waveform and so on, which goes 
on indefinitely (for devices other than DAQArb 5411 devices).

mode allows you to indicate whether to use FIFO mode waveform generation, if your device 
has a FIFO.

Range:

0 or 1 for most devices.
0 for all other devices.
1, 2, 3, or 4 for the DAQArb 5411 devices.

Table 2-41.  Mode Values for the Iterations Parameter for DAQArb 5411 Devices

0

not supported

1

0 for continuous cyclic waveform generation. 1 through 65,535 for 
programmed cyclic waveform generation.

3

iterations takes on a meaning of buffer ID. To load multiple buffers into 
the memory for arbitrary waveform generation, you can call 

WFM_Load

 a 

multiple number of times with mode set to 2. For the first buffer loaded, 
set the iterations parameter to 0. You must continue to increment the 
iterations parameter by 1 every time you call 

WFM_Load

 with mode = 2. 

The value of iterations parameter becomes the number I/D for that buffer 
being loaded. To generate those buffers, call 

WFM_Load

 with mode = 4. 

You can refer to those buffers by their buffer/ID.

Note: If you call 

WFM_Load

 in this mode with the iterations parameter 

not set to one more than it was for the previous 

WFM_Load

, you 

receive an error condition. You do not have to load all the previous 
buffers in such an error condition.You can load the new buffer with 
the corrected value for iterations parameter. Loading a buffer with 
the iterations parameter set to 0 clears all the previous buffers.

2

Ignored. Set it to 0.

4

Ignored. Set it to 0.