NI-DAQmx Tools for MATLAB 2009b or higher?

[lpm4ni]

I have come across several forums showing the same error as I get when I try to use the NI-DAQmx Toolbox shown here(http://zone.ni.com/devzone/cda/tut/p/id/3005).

Warning: LabVIEW MEX-File Error - Parameter 1: Failed

to load some MEX-function DLLs installed by The MathWorks,

Inc. MATLAB(R). These DLLs include libmx.dll and libmex.dll

They should be installed when MATLAB(R) is installed. Make

sure they are in the system's path.

There are some unofficial comments and posts all over the place, but I was hoping an NI representative could address this problem for me. Is this Toolbox compatible with newer versions of MATLAB, or is this Toolbox no longer maintained? The DAQ Toolbox provided by MATLAB does not allow you to acquire Single-Ended and Differential channels in the same task, despite the fact that all of the boards have that functionality, and it looks like the NI-DAQmx Toolbox will do the trick.

I'd hate to have to downgrade just so I can use the toolbox.

Thanks in advance for any replies.

[rpurser]

Hi,

What version of MATLAB are you using?  What NI device?  What version of Windows?  The new session based interface in the Data Acquisition Toolbox allows you to set single ended vs. differential on a per channel basis.  Exactly what devices are supported in what interface on which operating system varies with the version of MATLAB.  let me know what you've got, and we can help navigate that.

-Rob

[lpm4ni]

Hi Rob,

MATLAB Version 2009b, Windows 7 32-bit. Using NI USB-6218 devices.

Session-based seems to only be valid for CompactDAQ devices; why doesn't the Data Acquisition Toolbox let you take advantage of things that are already available on the device? We really need to configure simultaneous acquisition of single-ended and differential signals, so separating them into different analoginput objects won't suffice.

Any advice would be appreciated. Is there some combination of MATLAB/Windows that would allow session-based acquisition with a non-CompactDAQ device?

Cheers.

[manisha.singh]

Hi,

The prerelease of MATLAB R2011b supports non-CompactDAQ devices in Session-based interface. Session-based interface allows you to configure the terminal configuration ( single ended vs differential)  per channel basis. Session-based interface also works with 64-bit  MATLAB.

If you have a valid license,you can download prerelease from here.

Look at the example on this documentation page, you would need to change the InputType property of your channel object.

Hope that helps,

Manisha Singh

The MathWorks

[lpm4ni]

Hello,

Thank you kindly for the reply, that's great news. Following that documentation page shows how to add differently configured channels on two separate devices. Before I download and install the pre-release, can you confirm that I will be able to configure channels as Single-Ended or Differential on the same NI device (USB-6218)? And can you also confirm that acquisition on all channels will be synchronous, for a given device?

Thanks!

[manisha.singh]

Yes, you will be able to configure channels as Single-Ended or Differential on the same NI device

 s.Channels(1).InputType = 'SingleEnded'
s =
Data acquisition session using National Instruments hardware:
   Will run for 1 second (1000 scans) at 1000 scans/second.
   Number of channels: 2
      index Type Device Channel   MeasurementType        Range       Name
      ----- ---- ------ ------- ------------------- ---------------- ----
      1     ai   Dev8   ai1     Voltage (SingleEnd) -10 to +10 Volts
      2     ai   Dev8   ai2     Voltage (Diff)      -10 to +10 Volts

All ai channels on the same device will be synchronized.

Thanks,

Manisha

The MathWorks

[brycas]

Manisha,

Great news that Mathworks now provides support for session-based interfaces with many of the PCIe devices. However, my organization need access to higher speed digital I/O and we depend on the PCIe 6537 which is still only supported by the legacy mode. Is there ongoing development with future matlab revisions to support this particular card?

-BKC