DAQmx equivilent on OSX

[MatthewW]

We are trying to migrate all of our LV software from PC (running Windows XP, LV8, DAQmx) to several new and older Macs (all running OSX, LV8.2, and DAQmx Base). There are a fair number of vi's that make use of DAQmx functionality and this doesn't seem to migrate well to the OSX machines. Presumably this is because of the differences between mx Base and the usual DAQmx.

Is there an OSX equivalent to DAQmx for Windows? Have I just looked in all the wrong places?

Thanks for your time.

[johnsold]

Matthew,

DAQmx Base is the only driver NI offers for the Mac. Keep asking NI to give us all the functionality of DAQmx.

Check Info-LabVIEW. Urs Lauterburg has posted some information about extending the capability of Base. Base is written in LV, so extending it is feasible.

Lynn

[MatthewW]

Thanks for the quick response. It is baffling to me why NI would do such a thing but I suppose they have their reasons. I cannot seem to find anything useful at the infor-labview.org website. Is this what you meant?

[johnsold]

Try <> also. I think Brian's page is kept up to date, but I have not searched it recently. No code is posted to that mailing list, so you may need to read through the threads to find links or ideas.

Lynn

p.s., No comment on NI's reasons.

[pstys]

Hi Matthew:

Disclaimer: I'm a newcomer to LabVIEW, NI and mxBase on OS X. However, I've spent over a month trying to accomplish really simple things with mxBase on the Mac and it is driving me crazy. See my recent posts on the Multifunction DAQ forum and the NI engineers' responses: this convinces me that it's not my inexperience with this platform, but flagrant bugs in the driver that simply do not allow it to do what is advertised.

After several friendly responses from NI, I'm nowhere near accomplishing my very simple goals, and I encounter new show-stopping bugs at every turn (I'm about to post yet another).

This has been by far my most frustrating experience with any development platform. If base was written in LV, I'm prepared to get the full LV version and rewrite my own OS X framework (I see no alternative). Has anyone done this? Does it work? OR will I be faced with another 2 months of extreme frustration? Any comments from people who've tried?

Many thanks,
Peter.

[Neal M]

Hello Everyone,

Its interesting to point out that LabVIEW was initially written for Apple computers because it was the first graphical user interface.  When the PC became popular, most of NI's test and measurement customer base moved to the Windows operating system, so NI followed.  I personally believe a big factor in this was PCs were easier to customize (with the invention of the PCI bus). We did not want to completely block out all other operating systems, so NI developed a LabVIEW based driver (DAQmx Base) using our own Driver Development Kit for use on Mac, Linux, PDA, etc.  This driver is a subset of the functionality of DAQmx because so much of the DAQmx driver depends on the organization of the Windows OS.

I know that we are currently working on improving the functionality of DAQmx Base specifically and customer feedback has a very large impact on what features are developed.  I would strongly reccomend submitting a Product Suggestion outlining features you most would like to be included.  These suggestions are looked at directly by R&D (so they are not just thrown into the ether).

pstys,  I would be grateful if you would point me to where we are advertising functionality  that DAQmx base does not have.  I would like to submit a corrective action report so that we can fix any errors, to be sure that the correct information is available to the correct people. The last thing that NI wants is to promise functionality we cannot provide.

[pstys]

Hi Neal:

>>> I would be grateful if you would point me to where we are advertising functionality that DAQmx base does not have. I would like to submit a corrective action report so that we can fix any errors, to be sure that the correct information is available to the correct people. The last thing that NI wants is to promise functionality we cannot provide.

Happily:

Let's start with the mxBase 2.x C API docs (note that I've just tried a very small fraction of what's provided in this API, so there could me more issues):

1) DAQmxBaseCfgDigEdgeStartTrig: trigger edge is ignored and task starts as soon as DAQmxBaseStartTask is called (http://forums.ni.com/ni/board/message?board.id=250&message.id=36175&query.id=136430#M36175)

2) DAQmxBaseCfgSampClkTiming gives error with DAQmx_Val_FiniteSamps as the sampleMode param for DO tasks: big problem when you don't want the DO series to wrap around.

3) DAQmxBaseWriteDigitalU32: not at all obvious that numSampsPerChan can't exceed 2047 (http://forums.ni.com/ni/board/message?board.id=250&message.id=36174&query.id=136430#M36174). This severely limits the types of DO tasks you can do from a 2047 sample FIFO. Not so for AI/AO which is DMA and limited by RAM (I assume). So I assumed DI/DO would be similar, but no.

4) DAQmxBaseClearTask does not seem to clear a DO task. See my example in: http://forums.ni.com/ni/board/message?board.id=170&message.id=294549&query.id=136430#M294549. I can generate one DO task, but can't do a second identical task because of a time-out @ DAQmxBaseWriteDigitalU32. You have to reset the whole card with DAQmxBaseResetDevice, not helpful if you have other tasks running.

You can read details of these issues and other bugs that I found in my recent posts:
<>


This is just off the top of my head, there may have been other issues I've forgotten about.

Cheers,
Peter.

[Neal M]

Hello again Everyone,

Peter - I have looked at the forums you reference and talked with my collegues that you have been working with.  It appears that the best way to make sure you are sucessful with your application is to take this off the forums and work directly with you.  We can then post the results so that others can avoid similar issues.

MatthewW - If you have any issues using DAQmx Base, please feel free to post here on the forums.  As you can probably see, NI strives to make every customer sucessful with our products.