Advantech iDAQ-900 Series, Руководство пользователя

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iDAQ-900 User Manual 26
3.4 Analog Output
Insert an iDAQ module supporting analog output function to perform analog output
update/generation. The following sections describe the analog output update/genera -
tion mechanism. For detailed specifications of the functions, refer to the document of
the corresponding iDAQ module.
3.4.1 Static Analog Output Update
With static analog output update, the analog output voltage or current is updated only
when the software sends an “write static analog output sample” command. The ana -
log output voltage or current remains unchanged at other times. This is shown in Fig -
ure 3.17.
Figure 3.17 Static analog output update
3.4.2 Buffered Analog Output Waveform Generation
With buffered analog output waveform generation, the DAC conversion rate and the
duration of the generation is controlled by hardware timing signals. The analog output
waveform to be generated are first programmed and stored in the buffer memory in a
digital form. The digital values are converted to analog voltage or current one by one
for each sample clock as shown in Figure 3.18.
Figure 3.18 Buffered analog output waveform generation