Rif.: How to write/get program for Ocean Optics S2000-FL Spectrometer?

[Rannulph]

Programming Help for the Ocean Optics S2000-FL Fiber Optic Spectrometer


I am in need of a control program for the Ocean Optics, Inc. S2000-FL fiber optic spectrometer whether using a current driver, editing a previous, or writing from scratch. Any help or suggestions would be appreciated.

The control program should:

1) Accept acquisition parameters from the user, namely the wavelength(s) of interest to monitor, sample frequency, sample duration (i.e. run time)

2) Wait for contact closure to signal the start of acquisition

3) Once data acquisition has started, acquire signal amplitude at magnitude at the wavelength(s) of interest, and display them to the user as a function of time (intensi
ty versus time at specific wavelength). Sample rate will be low, on the order of 2-10 samples/sec. The idea is to display a peak response as a function of retention time as a sample flows through a laser-induced fluorescence detector on a capillary electrophoresis instrument.

4) Functions such as measuring retention time, peak integration, etc. from the data

5) Alternatively, each reading from the spectrometer, instead of being directly displayed to the user, may be written to a DAC, and the resulting analog output fed into a commercial chromatography workstation (which will accept a 0-1 V analog signal input) for display and analysis as conventional HPLC data. This would save us the task of developing and implementing such functions as measuring retention time, peak integration, etc.

Note: I have been looking at sample.vi program from the Ocean Optics drivers. Obstacles to overcome in order to use this program include converting data from intensity versus wavelength to
intensity versus time at specific wavelength(s) and functions such as measuring retention time, peak integration, etc.

Thank you very much for your help.

[LA 75]

Hello Rannulph,

I can certainly help you out looking for examples that you can use as reference for application and help you out in any specific questions you have about any of our products.

To start off working on this:

1. What DAQ card do you have?
2. What software (LabVIEW, CVI, etc) are you using and what versions are they?
3. Do you want to do analog input (AI) ,Digital input, counters?
4. How many channels are you going to use?

With all this we can get started with the program.

LA

[Steve Parus]

Are you using the serial port, ADC, or USB version ? I've used their
LV drivers to develop a LV program to do periodic Absorbance or
Fluorescence measurements over user specified wavelength ranges to
monitor titrations

Their stand-alone executable does intensity vs. time. I don't recall
if their LV driver has a specific frunction to perform that. If not,.
that info can be gotten by taking the sub-array portion of the spectra
that covers your desired wavelength range to be monitored vs. time.
It may be best to use a wavelength range rather than just one data
point (one wavelength) to average out any spikes or fluctuations. At
more than a few hundred millisecond integration times, the
spectrometer I've used had noise spikes one data point wide. These
were ea
slily removed using LV's Median Filter.vi.

It would not be difficult to take each reading and output the
corresponding value to a DAC. To convert from intensity versus
wavelength to intensity versus time at specific wavelength(s), you
have to take the data indices for each reading that correspond to your
wavelengh range and sum that range into an average. Retain that value
in an array as the intensity at that time point. Do you have an
existing DAC card ? How many wavelength ranges maximum do you want to
monitor at once ?

What language are you writing the application in ?

Alternatively, instead of using the Ocean Optics device, a photodiode
or photomultiplier detector coupled to an optical filter could be
used. Much less expensive. Possibly more sensitive and/or better
signal-to-noise ratio since the filter could span the entire emission
wavelength range. I'm in the process of putting together such a
system for LIF for CE and LC. Such a detectror would provide a direct
volta
ge output that could be used with your existing chromatography
data analysis. Is your LIF commercial or home-built ?

Steve

[Rannulph]

Thank you very much for your replies.

The current setup we have is an Ocean Optics S2000-FL spectrometer with an ADC2000 PCI-bus A/D converter. We have been using the Ocean Optics provided OOIBase32 software which outputs both a spectral plot of intensity versus wavelength, as well as plot of intensity at a specific wavelength versus time (timed acquisition mode). The problem is the OOIbase32 software does not analyze data (integration of peaks, retention time, etc).

Our application is to build a Laser Induced Fluorescence (LIF) detector for Capillary Electrophoresis (CE), apparently the same goal as Steve. We currently have the OO spectrometer and would like to use it, if possible. Although the photomultiplier approach might be more sensitive, it is not likely to be less expensive (based on purchasing new components). We have a homemade LIF flow cell, and want to take fluorescence readings and output an intensity versus time plot at a specific wavelength, detect & integrate the peak(s), measure retention time(s), etc. We would like the capability of analyzing at more than one wavelength if
possible.

We see two potential options on how to proceed: use our LabView version 7.1 to read from the A/D converter and analyze the acquired data directly, or to read a digital value from the spectrometer, write that data to a DAC board, and output a 0-1V signal to our existing Waters Millennium Chromatography software for analysis. Any suggestions, pros, or cons would be appreciated. Concerns we have include capabilities and ease of LabView to analyze data versus the complications of outputting an analog signal to the external chromatography software either direct from spectrometer (if possible) or through analog to digital back to analog. The D/A board we have is a ComputerBoards, Inc. CIO-DAS08-AO.

My LabView experience is minimal that said any help, advice or example/similar applications would be very much appreciated. Thank you very much for your help.

[LA 75]

Hello Ranuulph,

The advantages of using LabVIEW is that you can do all sort of analysis, and if you use one of our DAQ cards, you will also be able to acquire your data at very fast rates and very accurately. Also LabVIEW is really easy to use, it's much easier to learn than any text-based programming language I have ever dealt, and at the same time is very powerful. If you want to get a taste of the power and ease-of-use of LabVIEW, you can download a free 30 day trial version of LabVIEW 7.1 off from our website at ni.com.

Please let me know if you have any additional questions.

LA

[MAH2681]

I'm trying to do something similar to what was asked in the first message here but with a Bwtek spectrometer that uses a USB cable. I have Labview 7 Express. The spectrometer came with Labview examples to control the spectrometer but they seem complex and my Labview knowledge and experience isn't that great. I'm trying to control when the spectrometer would take data reading and how often and be able to take dark acquisitions and reference acquisitions as well and subtract their results. Also I need to be able to save the data. As of right now their example VI runs as soon as you push the Labview run button, I'm trying to stop this and have it run on another button, but haven't had any luck thus far. That's where I'm trying to start.


Any help or suggestions would be appreciated.


Thanks...

[einbrein]

I think that I have a question like the first.

I want to connect the Ocean Optics S2000 with the DAQ NI USB-6009.

Can you send, if it is possible, the wiring specification for DAQ NI USB-6009 to S2000 Production?

Thanks for your attention.

EB