User manual

Chapter 4: PowerDAQ Software (SDK)

Method C. Buffered polled-I/O waveform mode

See SDK Example AoutBlock.vbp

Buffered polled-I/O waveform mode does not require an event handler.

Instead, the analog output subsystem is initialized and the initial data is

written to the output buffer (2048 samples maximum).

After the subsystem and buffer have been initialized, the application

continues to write samples to the buffer. Since the board can only

accept a number of samples for which it has buffer space, the

application must keep track of the number of the samples it writes.

Buffered polled-I/O waveform mode is easier to implement than event-

based and it is a good mode to use in single-subsystem applications.

Initialization

• Reset analog output

# _PdAOutReset(…)

• Set analog output configuration

# _PdAOutSetCfg(…) set dwConfig =

AOB_CVSTART0 to use 11Mhz internal base clock

• Set timebase

# _PdAOutSetCvClk(…) use the same calculations to

set up timebase as it was described for analog

input subsystem

• Enable and start analog output waveform generation

# _PdAOutEnableConv(…) use 1 as dwEnable

# _PdAOutSwStartTrig(…)

Timer loop

• Write the Data

# _PdAOutPutBlock(…)