Has anyone used DDK with Mac OS X?

[julianv]

I am working with a group of neurophysiologists who have a custom data acquisition system running on aging 680*0 Macs, with Nubus-based NI boards. They want to port this system to run on the current PowerMac G4s, PCI-based NI series E boards, and Mac OS X. It looks like the "Preview" version of LabView for OS X is not yet mature enough to do this. When I called tech support, they told me that it might be possible to build a driver from the DDK, but that they will not provide any support.

I have written custom register-level drivers for boards before, but not for OS X. Has anyone else had success at this? Are there any sources for example code specific to OS X? Are there any significant issues in OS X which might make it d
ifficult? Our needs are rather pedestrian: we need to record from one or two ADC channels, at speeds up to 10k samples/sec, 12 bits per sample, perhaps for durations up to a minute. The users would like to monitor the data on screen as it comes in.

Thanks for any help.

[Tim_Ousley]

Julianv,

On OS X, you must write a kernel extension (kext) to interface to the PCI bus. The kext will need to match to the PCI card and provide an IOService that can map the PCI base address ranges into a process's memory.

The second piece is a .framework that wraps the .kext into the MH DDK iBus. This framework should match the .kext. MH DDK will link to the framework so that acquireBoard() and releaseBoard() call through the .framework into the .kext and map/unmap the PCI board.

That should be all you need to get the MH DDK to run on OS X.

I've attached a simple OS X project which builds a .kext which can map a PCI card's base addresses into user memory. I'd also recommend going through the Hello IOKit tutorial on the apple website.


Tim Ousley

[julianv]

Thanks for the leads, Tim. That looks like enough to get me started.

[RamziH]

Hi,

Can you please check the following link (http://developer.apple.com/sdk/); in the search field, type 'PCI' and you will get to many useful documents.

Regards,
RamziH.

[Melissa H.]

Any chance that the OS X driver has been "upgraded" to work with a more recent version of XCode? I'd prefer to avoid reinventing the wheel if possible. I have the .kext working for a PCI-6259 and am now working on the .framework.

Thanks,

Melissa

[Malcolm]

You can now also use NI-VISA to access PCI devices on Mac OS X.  You can then use the NI-VISA OS interface.

I'm curious why you are using MHDDK instead of NI-DAQmx Base for OS X.  Do you already have existing code running on MHDDK?

[Melissa H.]

---

@Malcolm wrote:

You can now also use NI-VISA to access PCI devices on Mac OS X.  You can then use the NI-VISA OS interface.

I'm curious why you are using MHDDK instead of NI-DAQmx Base for OS X.  Do you already have existing code running on MHDDK?

---

My hesistancy to use NI-DAQmx base is driven by the poor experience that others have had with it. In particular, I know that the WaveMetrics development team, for whom I have the highest regard, strongly suggested that people switch to PC rather than try to program with NI-DAQmx base. In fact, there poor experience led them to essentially drop support for NI-based data acquisition on the Mac. My needs are very specific, and so I should be able to use the DDK without too much problems. Unfortunately, there are many demands on my time these days, and I don't have as much time to spend programming as I would like. Hence my request. . .

If you would like more information on the problems as perceived by WaveMetrics, see

<>

Regards,

Melissa

[IanC]

it seems from this thread that it is posible to talk to a pci device (a pci-6259 m series card in my case) using NI-VISA running on mac OSX. I have found a lot of nice documentation for running GPIB instruments with NI-VISA on a mac, and probably usable instructions for running pci boards with NI-VISA from windows boxes, but i cannot seem to find anything on running pci cards like my m-series from a mac using NI-VISA. I'm wondering if there is anyone out there who has succesfully run a pci card (preferably a m-series, but at the moment i would take anything) using NI-VISA on mac OSX, and would be willing to share their expertece with me. Alright thank you all in advance.

[Thaison_V]

Hi IanC,

The Measurement Hardware DDK does use NI-VISA to communicate with PCI devices such as the M Series cards, and it is possible to do this on Mac OSX.  Maybe some of the other users can provide specific stories of their appliations using the DDK with these boards.

Thaison V

[IanC]

----The Measurement Hardware DDK does use NI-VISA to communicate with PCI devices such as the M Series cards, and it is possible to do this on Mac OSX. ----

I find it is not always easy to get an autoritative answer from NI on their less well known products, but I was told by a number of technicians that the DDk package would not work with the newer m-series cards. If you are sure it does work though I will check into it further. Thanks for your reply. Cheers.