MATLAB index of hardware channel or line
Note: You cannot use the legacy interface on 64-bit MATLAB®. See About the Session-Based Interface to acquire and generate data on a 64-bit MATLAB.
Every hardware channel (line) contained by a device object has
an associated MATLAB index that is used to reference that channel
(line). For example, to configure property values for an individual
channel, you must reference the channel through the
using the appropriate
Index value. Likewise, to
configure property values for an individual line, you must reference
the line through the
Line property using the appropriate
For channels (lines), you can assign indices automatically with
Channel (line) indices always begin at 1 and increase monotonically
up to the number of channels (lines) contained by the device object.
For channels, index assignments can also be made manually with the
For scanning hardware, the scan order follows the MATLAB index.
Therefore, the hardware channel associated with index 1 is sampled
first, the hardware channel associated with index 2 is sampled second,
and so on. To change the scan order, you can assign the channel IDs
to different indices using the
Index provides a convenient way to access
channels and lines programmatically.
AI, AO, per channel; DIO, per line
Read-only when running
Values are automatically defined when channels (lines) are added
to the device object with the
function. The default value is one.
Create the analog input object
ai for a sound
card and add two hardware channels to it.
ai = analoginput('winsound'); chans = addchannel(ai,1:2);
You can access the MATLAB indices for these channels with
Index1 = chans(1).Index; Index2 = chans(2).Index;