National Instruments PCIe-6323, User Manual

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5-1
5
Analog Output
Many X Series devices have analog output functionality. X Series devices that support analog
output have either two or four AO channels that are controlled by a single clock and are capable
of waveform generation. Refer to Appendix A,
Device-Specific Information , for information
about the capabilities of your device.
Figure 5-1 shows the analog output circuitry of X Series devices.
Figure 5-1. X Series Analog Output Circuitry
The main blocks featured in the X Series analog output circuitry are as follows:
• DACs —Digital-to-analog converters (DACs) convert digital codes to analog voltages.
• AO FIFO —The AO FIFO enables analog output waveform generation. It is a
first-in-first-out (FIFO) memory buffer between the computer and the DACs. It allows you
to download the points of a waveform to your X Series device without host computer
interaction.
• AO Sample Clock —The AO Sample Clock signal reads a sample from the DAC FIFO and
generates the AO voltage.
• AO Reference Selection —The AO reference selection signal allows you to change the
range of the analog outputs.
AO 2
AO 3
DAC2
DAC 3
AO D a t a AO FIFO
AO Sa mple Clock
AO Reference S elect
AO 0
AO 1
DAC0
DAC1