Neville D

True, the specs seem to point out that the device should work fine in terms of speed, but I've heard from others that sometimes in long term tests, MAX or the software appears to "lose track" of the device somehow, and the only way to bring it back is to unplug and replug the device back.

Just to be safe, I would use a PCI device for a neater solution (no external power brick required).

N.

Do you have to change the colors everytime? If you do it once during development mode, and save the VI, it remembers those colors.

N.

QUOTE (Dan Bookwalter @ Oct 23 2008, 06:15 AM)

I don't not have any of the NI Vision or IMAQ toolkits and wont be getting them.

I'm not trying to be negative here, but what's the motivation behind trying essentially a research-level project without the right set of tools?

With IMAQ you could probably threshold the images to highlight colors of interest (maybe bright colored clothes that a person might be wearing) and then try the Diff of the images. Or split the image into regions and try diff'ing just the regions.

Vision applications are usually quite complex however simple they may seem to (since everyone has eyes, and even a 1-year old can tell when someone's in the room) to the outside observer.

The jpeg file may not be the best for image processing. Try a non-lossy file format like png for better results.

Neville.

In the past where I had a very complicated GUI (20+plots, a few hundred Buttons and indicators) and the application ran on a laptop with a lower resolution monitor, and in the lab with a hi-res display, I actually made up two front panels, with identical code, except for the painfully adjusted layouts for the different resolutions.

At startup, queried the monitor resolution, and called up the appropriate code using VI-Server. For "in-between" values of resolution, I selected the front panel that fit the closest (generally the low-res VI).

But for maintenance its a bit of a pain, since you have to maintain essentially two (or more) top-level VI's.

Neville.

QUOTE (Phil Duncan @ Oct 23 2008, 08:37 AM)

Oh and to really complicate things, the acquisition duration is around 30ms, so around 20kS/s/channel minimum and the input voltage range is 0V-14V (I know the 6250 is only +/- 10V I am just using it for prototyping a concept).

You could use a voltage divider to step down 0-14V to 0-10V.

N.

QUOTE (David Wisti @ Oct 21 2008, 01:04 PM)

I would bet there is something wrong with DeviceClasses in the registry of your Dell desktop. Did could try deleting the USB flash disk in the device manager. Then, remove it and re-insert it so windows runs the found new hardware wizard. This might fix your registry and MAX might work.

There is no action to delete the device under the Device Manager. It simply shows up as "USB Composite Device". I can only disable it.

I think the problem is that this DELL has a memory card reader connected via USB internally and that might be interfering with the drive letters F, G, H, I, so the utility fails when trying to load software to the appropriate drive. Anyway, it worked with the laptop.

N.

Which specific VI was it? If its a Vision related VI, goto Add-Remove programs and "repair" the NI Vision/NI IMAQ install. So you don't have to re-install everything all over again.

Alternately, if you have another installation with the same version of everything, copy over the VI from the good installation.

Neville.

QUOTE (LV_FPGA_SE @ Oct 21 2008, 11:05 AM)

You could try and see if there is anything else in the System Hardware Device Manager that may be interpreted as a USB device by the OS. For example is there something internal to your computer that is connected to the motherboard using USB.

Another thing to try is to copy the folder, subfolders and contents of the directory containing the USBFORMAT utility (C:\Program Files\National Instruments\RT Images\Utilities\PXI_Disk\8.5.1\) to another (hopefully different) computer and run the utility there on your USB drive.

Hey that was a good hint! I tried my laptop and it worked!

I guess there are a lot of things connected internally via USB in my DELL desktop.

Thanks!

N.

Maybe a note should be added to the http://digital.ni.com/public.nsf/websearch/9209361E17708D548625744A007FF353?OpenDocument' target="_blank">NI link about this.

Also take a look at the Resample ExpressVI.

Neville.

Do you have the IMAQ or vision package installed? I don't think you would be able to save the images unless you have them.

There is a VI Under Vision Utilities>Files>IMAQ write File. It is polymorphic and can save images as jpg, png, bmp, tiff and jpg2000.

Neville.

QUOTE (LV_FPGA_SE @ Oct 21 2008, 07:27 AM)

N.,

I'm not sure if it will make a difference, but can you try the following command line command to setup the USB memory.

Please remove as many other USB devices as possible from your system before running this, especially any that may contain memory or act as a drive (external harddrive, digital camera, iPod, etc.). Keyboard and mouse should be okay.

C:\Program Files\National Instruments\RT Images\Utilities\PXI_Disk\8.5.1\usbformat.exe usb

Update the drive letter and version number for your installation.

Hi Christian,

I tried exactly that yesterday from looking at the links. It seemed to run without error, but nothing was generated on the USB stick.

I tried 8.5.1 and 8.6.

Is there any way to specify the drive letter in the command line?

Neville.

QUOTE (crelf @ Oct 20 2008, 12:08 PM)

I'm not sure I understand - can you explain those two items a bit further?

Hi Chris,

Sorry, having internet troubles at work. I was trying to test whether my desktop could be used as an RT target.

Following the http://digital.ni.com/public.nsf/websearch/9209361E17708D548625744A007FF353?OpenDocument' target="_blank">instructions, I wasn't able to create the USB stick-based utility to test it out.

Using the command from NI-MAX>Tools>RT Disk Utilities>Create Desktop PC Utility USB Drive

fails with "USB device not found".

I can also try building a floppy disk with the utility according to the link, but I have neither a floppy drive nor a floppy, and it seems crazy to try to hunt all that down and try to make it work with a modern quad-core Dell.

Your link was somewhat helpful, but I am still at sea.

N.

QUOTE (TobyD @ Oct 20 2008, 11:28 AM)

you might try formatting your USB drive using the http://www.pcworld.com/downloads/file/fid,64963-order,4-page,1-c,peripherals/description.html' rel='nofollow' target="_blank">HP USB Disk Storage Format Tool. I have found other applications where a drive formatted in windows was not readable, but one formatted with the HP utility was.

I tried the HP utility but MAX still can't find the USB drive. Aargh!

Thanks Toby.

N.

I am trying to create a desktop PC Utility on a USB memory stick in order to test requirements for turning a desktop into an RT target.

But the darn MAX utility simply refuses to recognize a perfectly good USB memory stick that has been correctly formatted as FAT32.

I tried two different USB sticks, and different USB ports.

Any ideas?

Neville.

QUOTE (MasonJar @ Oct 17 2008, 04:46 PM)

I think the gain is too low.....and been putting off the call to NI.....but maybe it is time. And the SCXI might be the answer. I sometimes think NI was advertising the "E" series boards as being TC compatible....but with what accessories??

As far as those panel displays.....have you ever worked with NI Dasylab?? It is super easy to learn and user friendly. Version 8 or 9 is now compatible with the NI-DAQmx. That's why I am trying the NI boards.

I checked the NI catalog... it doesn't mention anything about TC mmt with E-series; it does mention signal range of measurement 50mV to 10V for the E-6071, with only 12bits resolution, absolute accuracy of the range of only 15mv!! No wonder your TC's are "jumpy".

However, another solution is to get the SCC hardware and the SCC-TC series hardware to add-on to your E-Series card. Again, the chassis (SCC carrier) and modules are all separate giving you lots of flexibility for cost that is less than SCXI, but probably an additional $1000.

Or you could get M-Series Hardware.

Basically, all recommendations hinge on the #of TC channs. What are your requirements?

N.

PS I have never used Dasylab.

QUOTE (MasonJar @ Oct 17 2008, 02:07 PM)

The 6071E does have 10 different gain ranges and the highest setting is 100. In the old MMC/expansion boards...all TC's were set at a gain of 200 which allowas 0 - 50 mV range. That's why I am thinking the TC's may be "down in the mud" with the 6071E.

Yes, therein lies the problem. The SCXI adds a pre-amp stage gain of atleast 500 to 1000, that can be then multiplied by the DAQ card's gain. The SCXI channels are all multiplexed into a single channel on the DAQ card so essentially you need both. But this is a very expensive option. Depending on #channels it can work out affordable if you have a lot of different channels with different (and widely differing) gain requirements.

You can use an SCXI chassis + card with any NI DAQ card that has AI channels as far as I can remember. You will need a chassis, the relevant SCXI card, cable, and breakout board.

QUOTE (MasonJar @ Oct 17 2008, 02:07 PM)

Yes, it probably won't make a difference, the problem is the gain is too low.

QUOTE (MasonJar @ Oct 17 2008, 02:07 PM)

True, maybe a call to NI support is in order? Two other options are:

1 If you have the odd TC channel here or there, get an Omega Temperature reader (about $130 if I remember right), connect the TC to those, and these usually have a 0-5V out or 0-10V output proportional to the temperature and read those in with the DAQ. Again depends how many channels you have. This also gives you a nice digital panel display of the temperature and have all kinds of fancy alarms changing the color of the temperature etc. (programming these is a major pain, but thats another issue). I have used these in the past and have worked very well.

2 Check with NI support and get a more expensive M-Series or S-Series (I'm not sure which will work better for you) with larger gain, maybe you can swap your E-Series for one of those if 30days are not up? Pick one that uses similar cable/breakout board and you can re-use all of that.

N.

QUOTE (Louis Manfredi @ Oct 17 2008, 11:48 AM)

I've found the documentation for 653x DaqMX a little cryptic, and for things like figuring out how to use external sample clock input, hardware triggering, and the like, you need to refer also to the traditional nidaq documentation, which is more thorough, but unfortunately seems to use different signal names, from the Daqmx. Count on needing a little patience to understand this hardware's finer points.

True, the old-style documentation is a lot more thorough, and carefully walks you through steps of making different types of measurements. Some of those pdf's don't even ship with Labview any more :thumbdown: . NI seems to rely more and more on clunky "help" files that are no help.

That said, the DAQmx API is indeed fast, multi-threaded and very powerful.

N.

What if you set the CJC manually to approx room temperature 25degC? I remember there was an option in MAX to do that.

I suspect your problems are because you have specified too wide a range of temperatures to be measured with your thermocouple. That sets the gain to make sure the whole mmt range is covered, which means none of the range is covered very well.

Also the cheaper cards like the 6071 or the USB units have a courser gain selection (or the gain doesn't go high enough), so if you fall between the ranges, and the more conservative range is selected the SNR will be degraded. The TC outputs are in the microvolts range as you probably know.

Try setting temp mmt range to say 0-100deg and see if it helps.

In the past I had problems with thermocouples and PCI daq cards, so we switched over to SCXI and the temp mmts were great with the additional pre-amp gains added by the SCXI modules.

Sorry I haven't played with DAQ in a few years but thats what I remember.

N.

Having more memory onboard means you have to query the card less often when reading the data off of it.

Also try to get a card that supports DMA (and the more DMA channels the better). This helps with simultaneous AI and AO if you need it.

But really the biggest advantage with using NI is the seamless support with Labview/Daqmx. You won't get that with any non-NI cards, and for that reason alone I would stay away from them.

Obviously, if you need a specialized function that is not available on an NI product then you would be forced to deal with all the integration issues of getting the non-NI product to work well with the rest of your LV code.

Neville.

Do you have anything "known good" to compare with? Controller? Chassis? software version?

Start with that and swap things out till it fails.

N.

Getting any errors? I notice that an error won't necessarily stop your code, but keep running (from what little I can see of the attached jpeg).

Have you tried running a simpler counter example ?

Check the counter settings to see if they exactly match the ones that are working in MAX.

N.

QUOTE (Yossi @ Oct 14 2008, 06:55 AM)

When I sample a nice signal (almost with out noise), I get it nice but some times I get spikes in the voltage samples, of about 100mv to 400 mV. I'm using the S series, so this is not cross talk, so do you have any idea what can cause such phenomena?

Bad ground? Do you see the spikes with an oscilloscope as well? Does the card you are using have isolated channels? I find the best way NOT to have noise issues is to use isolated channels, but this can get expensive pretty quickly.

N.

QUOTE (Götz Becker @ Oct 7 2008, 04:51 AM)

Perforce is currently set for all our projects and I fear that mixing SCCs would do more harm than good.

True.

QUOTE (Götz Becker @ Oct 7 2008, 04:51 AM)

I meant just duplicate your current project, throw out all the conditional disable's and see if that speeds things up. Just as a test. That way you can narrow down the problem to Perforce or NI.

N.

QUOTE (Götz Becker @ Oct 6 2008, 01:56 AM)

NevilleD: Are you using SCC? If so which?

Your questions:

2: compiling for one PXI target only, but many VIs having conditional disable symbols inside shared VIs between Windows HostApp and RT

I use Source Safe. I just check out the VI's, work on them and check them back in. No llb's.

Have you tried a project without the conditional disable's to see if thats causing the slowdown? Might be worth investigating. 10-20mins seems like a lot of time wasted for a build.

I have heard that NI uses Perforce too, and I'm sure they would have found a workaround to slow builds if they faced the problem, so maybe it is not related to Perforce or else you are using it in a different way thats causing the slowdown.

Maybe you can investigate Tortoise SVN. Lots of people on LAVA have good things to say about it; also its free.

N.

QUOTE (sahara agrasen @ Oct 2 2008, 08:28 PM)

also ni week 08 summit presntatoin are not viewable.

?? Did you even try? They are all PDF documents that can be downloaded. There are a couple of presentations describing applications (I don't remember off the top of my head, but look at the TOCAMAC reactor one, it uses PXI if I remember correctly).

Even with slow internet connection that should be possible to download.

N.