Data Acquisition Toolbox

length

Return the length of a device object, channel group, or line group

Syntax

out = length(obj)
out = length(obj.Channel)
out = length(obj.Line)

Arguments

obj	A device object or array of device objects.
obj.Channel	The channels contained by obj.
obj.Line	The lines contained by obj.
out	A double.

Description

out = length(obj) returns the length of the device object obj to out.

out = length(obj.Channel) returns the length of the channel group contained by obj.

out = length(obj.Line) returns the length of the line group contained by obj.

Example

Create the analog input object ai for a National Instruments board and add eight channels to it.

ai = analoginput('nidaq',1);
aich = addchannel(ai,0:7);

Create the analog output object ao for a National Instruments board, add one channel to it, and create the device object array aiao.

ao = analogoutput('nidaq',1);
aoch = addchannel(ao,0);
aiao = [ai ao]

Index:    Subsystem:         Name:
   1         Analog Input       nidaq1-AI
   2         Analog Output      nidaq1-AO

To find the length of aiao

length(aiao)
ans =
     2

To find the length of the analog input channel group

length(aich)
ans =
     8

See Also

Functions

size

isvalid

load