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Analog output, Connecting analog output signals – National Instruments NI 783xR User Manual

Page 33

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Chapter 2

Hardware Overview of the NI 783xR

NI 783xR User Manual

2-14

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Analog Output

The bipolar output range of the NI 783xR AO channels is fixed at

±10 V.

Some applications require that the AO channels power on to known voltage
levels. To set the power-on levels, you can configure the NI 783xR to load
and run a VI when the system powers on. The VI can set the AO channels
to the desired voltage levels. The VI interprets data written to the DAC in
two’s complement format. Table 2-3 shows the ideal AO voltage generated
for a given input code.

Note

If your VI does not set the output value for an AO channel, then the AO channel

voltage output will be undefined.

Connecting Analog Output Signals

The AO signals are AO <0..n> and AOGND.

AO <0..n> are the AO channels. AOGND is the ground reference signal for
the AO channels.

Figure 2-9 shows how to make AO connections to the NI 783xR.

Table 2-3. Ideal Output Voltage and Input Code Mapping

Output Description

AO Voltage

Input Code (Hex)

(Two’s Complement)

Full-scale range –1 LSB

9.999695

7FFF

Full-scale range –2 LSB

9.999390

7FFE

Midscale

0.000000

0000

Negative full-scale range,
+1 LSB

–9.999695

8001

Negative full-scale range

–10.000000

8000

Any output voltage

AO Voltage

10.0 V

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