Programming instructions

Chapter 4 Where You Should Go Next
LabVIEW Data Acquisition Basics Manual 4-4
© National Instruments Corporation
4. Single-Point or Multiple-Point Acquisition?
Do you want to acquire a signal value(s) at one time or over a period of
time at a certain rate? If you measure a signal at a given instant of time,
you are performing
single-point acquisition
. If you measure signals over a
period of time at a certain rate, then you are performing
multiple-point or
waveform acquisition
.
If you want single-point acquisition, refer to Chapter 6,
One-Stop
Single-Point Acquisition
. If you want multiple-point acquisition, read
question 6.
5. Single-Point or Multiple-Point Generation?
Are you outputting a steady (DC) signal or are you generating a changing
signal at a certain rate? A constant or slowly-changing signal output is
called
single-point generation
. The output of a changing signal at a certain
rate is called
multiple-point
or
waveform generation
.
If you want to perform single-point generation, refer to Chapter 11,
One-Stop Single-Point Generation
. If you want multiple point generation,
refer to Chapter 12,
Buffering Your Way through Waveform Generation
.
6. Triggering a Signal or Using a Clock?
You can start an analog acquisition when a certain analog or digital value
occurs by
triggering
the acquisition.
If you want to trigger an analog acquisition, refer to Chapter 8,
Controlling
Your Acquisition with Triggers
.
Multiple-Point Acquisition with an Internal or External Clock?
Multiple point or waveform acquisition can be done at a rate set by an
internal DAQ device clock or an external clock. The external clock will be
a TTL signal produced at a certain rate.
If you want to acquire a waveform at the rate of an external signal, refer to
Chapter 9,
Letting an Outside Source Control Your Acquisition Rate
. If not,
read Chapter 7,
Buffering Your Way through Waveform Acquisition
.