National Instruments Welding System 321645c-01 Manual De Usuario

Chapter 2

Function Reference — WFM_Group_Control

NI-DAQ FRM for PC Compatibles

2-420

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 National Instruments Corporation

Controls waveform generation for a group of analog output channels.

group is the group of analog output channels (see 

WFM_Group_Setup

).

Range:

1 for most devices.
1 or 2 for the AT-AO-6/10.

operation selects the operation NI-DAQ is to perform for the group of output channels.
operation = 0 (CLEAR): Terminates a waveform operation for the group of analog output 

channels. The last voltage produced at the DAC is maintained 
indefinitely. After you execute CLEAR for an analog output 
group, you must call 

WFM_Load

 before you can restart waveform 

generation using operation = START.
(AT-MIO-16F-5 only) If you aligned the data buffer used in the 
waveform generation by calling 

Align_DMA_Buffer

, CLEAR 

unaligns the buffer. That is, the data samples start at index 0 of the 
buffer. If you want to use the same buffer again for waveform 
generation, you must call 

Align_DMA_Buffer

 again before 

calling 

WFM_Load

.

operation = 1 (START):

Initiates waveform generation at the analog output channels in 
group. Your application must call operation = CLEAR before 
terminating, if START is executed. If you do not execute CLEAR, 
unpredictable behavior might result.

i16

assigned by configuration utility

i16

group of analog output channels

i16

operation to be performed