Programming instructions

Chapter 3 Basic LabVIEW Data Acquisition Concepts

National Instruments Corporation 3-11 LabVIEW Data Acquisition Basics Manual

are your channels, you can specify a list of channels in a single element by

separating the individual channels by commas—for example,

0, 1, 2

Or,because

refers to the first channel in a consecutive channel range and

refers to the last channel, you can specify the range by separating the first

and last channels with a colon—for example,

0:2

Some Easy and Advanced Digital VIs and Intermediate Counter VIs only

need one port or counter to be specified. For more information, refer to the

LabVIEW Function and VI Reference Manual

or the LabVIEW

Online

Reference

. Choose

Help

Show Help

and put your cursor on the VI to view

the VI Help window for the VI you intend to use.

LabVIEW recognizes three types of analog channels on a DAQ device:

onboard, AMUX-64T, and SCXI channels. It recognizes two types of

digital ports and counters: onboard and SCXI. This section describes

addressing onboard channels, ports, and counters. AMUX-64T

addressingis described later in Chapter5,

Things You Should Know

aboutAnalogInput

. SCXI channel, port, and counter addressing is

described in Chapter18,

Things You Should Know aboutSCXI

Onboard channels refer to analog or digital I/O channels provided by the

plug-in DAQ device. If

is an onboard channel, you can specify this by

entering

OBx

as the

channel list

element. Refer to the description of

your device in your hardware user manual for restrictions on channel order.

Figure3-7 shows several ways you can address onboard channels

, and

. The top three examples apply to VIs whose channel parameters are string

arrays. The bottom two examples apply to VIs whose channel parameters

are scalar strings.

Figure 3-7.

Channel String Array Controls