User manual

Chapter 3 Software Overview
NI-DAQ User Manual for PC Compatibles 3-36 ni.com
AO_VScale
Scales a voltage to a binary value that,
when written to one of the analog output
channels, produces the specified voltage.
AO_VWrite
Accepts a floating-point voltage value,
scales it to the proper binary number, and
writes that number to an analog output
channel to change the output voltage.
AO_Write
Writes a binary value to one of the analog
output channels, changing the voltage
produced at the channel.
Analog Output Application Tips
This section contains a basic explanation of how to construct an application
using the analog output functions. The flowcharts are a quick reference for
constructing potential applications from the NI-DAQ function calls.
For most purposes,
AO_VWrite
is the only function required to generate
single analog voltages. It converts the floating-point voltage to binary and
writes the value to the device.
AO_VWrite
is the equivalent of a call to
AO_VScale
followed by a call to
AO_Write
. Figure 3-12 illustrates the
equivalency.
Figure 3-12. Equivalent Analog Output Calls
The following applications are shown using
AO_VWrite
.However,
substituting the equivalent
AO_VScale
and
AO_Write
calls will not
change the results.
AO_VWrite
AO_Write
AO_VScale
Scale floating-point voltage to
binary value.
Output binary voltage to board.
Scale floating-point voltage
to binary value and output
binary voltage to board.