Problems with Data Aquisition Toolbox 2.17 and National Instruments cDAQ-9172

I use Matlab R2010b and have some problems with data acquisition.

I connected a National Instruments cDAQ-9172 chassis via USB and plugged in a NI-9201 analog input module. To acquire data I used the session-based interface like described in chapter 9 (page 9-8) in the user-guide of the data acquisition toolbox. Everything worked fine.

But then, I wanted to use Matlab Simulink to acquire data. I opened the Data Acquisition block library and added the Analog Input block to my model. When I wanted to specify the block parameters the only device that was shown is my soundcard. Why did not appear the cDAQ-Chassis there?

I installed the NI-DAQmx drivers as well as the "old" traditional drivers (Version 7.3).

Answer 1

[Shankar Subramanian]

The Data Acquisition Toolbox Simulink Library does not support cDAQ devices yet. Only the MATLAB API supports CompactDAQ devices. This is the reason that you are not seeing the cDAQ devices connected to your system when you drop Analog Input/Output blocks in the model. One way to work around this is to write MATLAB function to acquire data and bring it into Simulink using the MATLAB function block.

HTH, Shankar

[MoeIsKing]

That is just bad to be honest...

yes you can write an m file to acquire your data and then just "import" it into simulink...

booo

boooo

would be nice if you work on a direct implementation into simulink like the data acquisition toolbox gives in matlab, just unthinkable that it won't integrate to simulink nicely :-/

Answer 2

[Walter Roberson]

A card connected through a USB must be doing digital I/O. The Analog Input block is for directly attached A/D cards, I believe.

A device connected via USB has a lot more complications and timing problems and throughput problems than a directly attached device.