Programming instructions

Chapter 4 Where You Should Go Next
© National Instruments Corporation 4-5 LabVIEW Data Acquisition Basics Manual
7. Non-Latched or Latched Digital I/O?
If you want your program to read the latest digital input or immediately
write a new digital output value, you should use non-latched (immediate)
digital I/O. When a DAQ device accepts or transfers data after a digital
pulse has been received, it is called latched (handshaked) digital I/O. With
latched digital I/O, you can store the values you want to transfer in a buffer.
Only one value will be transferred after each handshaked pulse.
If you want to use non-latched (immediate) digital I/O, refer to Chapter 16,
When You Need It Now— Immediate Digital I/O
. If you need to perform
latched (handshaked) digital I/O, refer to Chapter 17,
Shaking Hands with
a Digital Partner
.
8. Counters: Counting or Generating Digital Pulses?
If you want to generate digital pulses from a counter at a certain rate, read
Chapter 24,
Generating a Square Pulse or Pulse Trains
. If you want to
measure the width of a digital pulse, refer to Chapter 25,
Measuring Pulse
Width
. If you want to measure the frequency or period of a digital signal,
refer to Chapter 26,
Measuring Frequency and Period
. If you just want to
count how many times a digital signal rises or falls, refer to Chapter 27,
Counting Signal Highs and Lows
. To learn how to slow the frequency of a
digital signal, refer to Chapter 28,
Dividing Frequencies.