Tim_S

Who are they? I think I have some ISA VGA cards and 2400 baud modems at home I'd like to sell them. I was able to locate 10M and 100M but no 1Gbit. I recommend, should you find such a device, that you start looking for 4-leaf clovers and playing the lottery. Tim

wincraze83 - You're not giving a lot to help you with. You'll need a servo driver and that will be controlled by some digital I/O or comm I/O depending on the driver. The driver may have seperate enable lines and interface with an E-Stop circuit, or it may be a "dumb device" with no safety circuits built in. You may be able to connect TTL level signals to it, you might not. There may be an analog output for speed feedback, there may be an encoder, and there may be nothing so you have to add a speed pickup. You're going to need to research and make some design decisions based on what you are doing with this motor. Tim

You don't mention what hardware you have nor what type of DC motor (stepper? permanent magnet? servo?). Tim

I'm curious why you're using this method rather than using the DAQmx Flatten Channel String VI? Tim

Any motor and driver can generate a lot of electrical noise that can fry elctronics connected to them. I think sachsm is right about optoisolation. The PWM controller may have sufficient isolation on its own; it should be OK if it accepts TTL inputs, though a little paranoia is not a bad thing. Otherwise, you'll want to be careful of your grounds, EMI and routing of cables. I've seen 12V solenoids create electrical noise on shielded twisted pair analog inputs when switching the solenoid. Tim

I notice from your sig that you're an undergraduate. I take it this is a project for a class? I'm not too familiar with the image processing toolkits. Have you gone through the pallets and checked out the help? Tim

Is there a reason you're not using C++ to read the TCP message? I think we might be able to assist you better if you can post what you've done in your DLL. You could send a timestamp with the request, however you'd have to synchonize the clocks at the client and server. Tim

Extend your time sample if you are just looking to increase the df (df ~ 1/T where T is the time length). You may want to look at a Zoom FFT in the Sound & Vibraion Measurement Suite if you are only looking at a small portion of the frequency range. Tim

Can't have too many chickens about. Can't say I have had good luck with memory deallocation either, but the times I have tried it I wound up redesigning chunks because what I was doing required going back and checking my sanity. As a thought, that is a lot of data to display and can't have everything visible on a graph. Can you read in from file and decimate to something somewhat sane? This may be quite slow, but trying to keep everything xN copies in memory would also slow the machine down. Tim

Ah, the evilness that is copies of data. Have you... - Reduced the number of subVIs - Tried using Request Deallocation - (LV2009) tried passing by-reference data - Attempted to use smaller chunks at once - waved the dead chicken Tim

One day we will have robots following us about to inject happy drugs. Sorry, been reading too much Sluggy Freelance lately... Curious... what are you doing that you need 2GB chunk at once? Not that I haven't had Windows take down LV for exceeding 2GB... Tim

I agree with asbo... Your best bet would be to open a source and create a target file as binary and to read/write out chunks, updating a progress bar every N-th itteration of your loop. There is a JKI progress bar (I believe it's in the Code Repository) that may help you out with that portion. Three minutes with the user wondering if the program is locked. My experience is users do not have much patience and have a tendency to kill programs that they think aren't responding.

I consider it good practice to open the VISA connection and then clear out any "garbage" that may be sitting in the buffer. I don't see how it'd be necessary before closing a connection. Tim

I missed the difference in number; I thought that USB 6220 was typed instead of 6210. Drat, that little difference could be huge. Tim

A block diagram is always better when asking questions. The issue may be on the end of the o-scope; I expect you'll need to call their technical support. Tim

I did a bit of poking about and discovered two articles: http://forums.ni.com/ni/board/message?board.id=170&message.id=123821 http://newsgroups.derkeiler.com/Archive/Comp/comp.lang.labview/2008-02/msg00510.html I tried the 'UseUnicode=TRUE' with Chinese characters and that seems to have worked. Labels don't seem to take unicode, but button text and string text seem to accept them. Tim

LabVIEW doesn't support unicode characters, but does support wide characters. I've not been able to get wide characters to display Chinese yet, so I'd like to know if you manage to get Greek characters to display. There are some third party controls that can be dropped into LabVIEW that can add unicode support; appologies that I don't have a link at the moment to point you to them. Tim

Same answer as with numeric data types. Tim

Try putting an array into the comparison. The output will switch between a single boolean and an array of booleans as you switch between comparing elements and agregates. Tim

The wording of your questions is a little confusing. If you mean you want to know if you can take a PCI board and make it a USB board, then it is possible, but you'd be far, far better off just buying the USB variant as you'd be developing your own PCI to USB bridge and software drivers. If you mean changing the software to use a USB-6220 instead of a PCI-6220, then that's a mere matter of switching the physical channel you're measuring in your software. Tim

The example works, however there is a constant on the block diagram for the register address. You may also need to switch betwen input and holding registers. Appologies that I can't be more helpful right now. Tim

A lookup table works well for multiple-language support. My company has used them for LabVIEW and non-LabVIEW programs. The difficulties you can get into are in attempting to reuse messages for the same type of error (e.g., file not found) and ensuring there is sufficient space for the text for all languages. You've not mentioned Chinese or Russian, so unicode characters shouldn't be a concern. Tim

My best guess is you need to set the address, change from input registers to holding registers, and set the correct number of words you want to read. The Modbus spec (see David Wisti's link) is pretty readable and does contain the error codes you'll get back from the device. One caveat about Modbus addresses is the address you need to request may not be the one documented by the manufacturer, but it will be near that address (+/- a couple); I've found this to be the case on Festo and Cuttler Hammer equipment (to boot the PLC and PC request different addresses for the same register... arg!). Tim

I've used to example/library from the NI website with success. The code does work. Timeout out with serial would tend to indicate to me that there was no response. You should get error messages if you are talking to the device. My first suggestions would be physical. Are you plugged in on both ends? Are you plugged into where you think you are? Do you have a null-modem cable when you need a strait-through or visa-versa? Is the device on? Tim