National Instruments PCI-6251 User Manual

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5
Analog Output
Many M Series devices have analog output functionality. M 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 the specifications document for your device for information
about the capabilities of your device.
Figure 5-1 shows the analog output circuitry of M Series devices.
Figure 5-1. M Series Analog Output Circuitry
The main blocks featured in the M 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 M 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 Offset and AO Reference Selection—AO offset and AO reference selection signals
allow you to change the range of the analog outputs.
AO 2
AO 3
DAC2
DAC3
AO Data
AO FIFO
AO Sample Clock
AO Offset Select
AO Reference Select
AO 0
AO 1
DAC0
DAC1

National Instruments PCI-6251 Specifications

General

Brand	National Instruments
Model	PCI-6251
Category	I/O Systems
Language	English