06-05-2009 12:09 AM
Hi,
I have used USB4000 spectrometer with LabVIEW 8.6.
However i have avoided the use of the DLL`s provided
by ocean optics . They are very unstable , hence I have
used the COM objectsdireclty in LabVIEW ; which seem
to be much more stable than DLL`s provided by ocean optics.
Sundar.
06-05-2009 12:31 AM
Hi Lynn
We are not affected by speed limitations but we may not need the aquisition to be as fast as someone else. The driver comes with samples in several languages so it would be easy for you to try / switch languages to see if any provides a speed advantage for the rate at which you need to aquire data. Here at home I cannot confirm this because I dont have a spectrometer but I see several examples have a EXE that may work without you having to compile the application yourself.
At any rate the driver works with many languages so you risk nothing when you get it. There is even a sample for NI CVI . I have not tried to use with other languages except LabView. The LabView driver is a DLL that gets called by vis that are part of a library.
We have one station ( plus others not as fast ) that measures a laser spectrum as part of the test and on a busy day it tests up 800 tests. This station runs 2 shifts 5 days a week and we dont have any problems with the LabView application that uses the driver. Do not get the OOILVD. Get the new OmnDiver which has the LabView libray called Wrapper.llb and the DLL called OmniDriver32.dll
Mario
06-09-2009 08:47 PM
Hi Sundar,
Thanks for your information.
Regards,
Lynn
06-09-2009 08:55 PM
Hi Mario,
Thanks for your information. I also would like to ask you if you have been used Labview for wireless data acquistion system.
As much as I know and as my experience, mostly Labview is programmed to do data acquistion through the cable like RS 232. Now I has a plan to do wireless data acquistion with Labview.
If you have experince with this, please give me some comment.
Best Regards,
Lynn
06-09-2009 11:26 PM
Hi Lynn
No I dont have any experience doing wireless but NI has hardware for that and I would expect it will work just fine.
I do alot of DAQ but mostly via PC slot card and USB ( not technically RS232). Theres also Field Point and ehternet so lots of choices and they all should work fine.
Thankfully NI software works with almost any hardware and is very well implimented and reliable.
Mario
06-10-2009 12:14 AM
Thanks, Mario.
Regards,
Lynn
06-30-2009 09:33 PM
Just to throw in my 2 cents - the OmniDriver package is buggy, but some of the problems people are having may be due to the firmware version of the USB4000 itself. My company had no end of problems with these spectrometers freezing up randomly, where they just kept returning the same spectrum. We used the OceanOptics USBProgrammer software to update the firmware and many of the problems went away.
We also did a quick noise comparison of the 4000 to the 2000 and 2000+. The 2000+ had far lower pixel noise than the 4000... and the firmware has never given us a problem.
Sundar - I'd really like to see how your drivers work. Any chance you could make them available? Thanks in advance...
06-30-2009 10:31 PM
I can certainly agree with the pixel noise factor, something often totally overlooked when evaluating a spectrometer......
CMOS-Sensor based spectrometers tend to have much better signal to noise ratios than CCD....
Shane
06-30-2009 10:50 PM
Hi Jason,
You are very true. The Omni drivers are quite buggy, specially the DLL interface; they lack even a basic error handling functionality.
So instead I have tried to use the COM interface that is registered with the windows environment while the OMNISPAM is installed.
I haven't seen any application crashes after using this method with error handling incorporated in LabVIEW.
However let me see if I can provide the drivers i have built .
Sundar.
06-30-2009 10:57 PM
Very true. SNR is very critical in evaluating a spectrometer to derive the best results.
To an extent this can controlled with use of appropriate use of filters in the application.
but however one has to have a clear understanding of the noise factor for it tobe minimized.
Sundar.