Development of a real-time digital acquisition software system for the Ocean Optics S1000 spectrometer

Stephen Andrew Fennell (Thesis), Dublin Institute of Technology

Document Type Theses, Masters

Successfully submitted for the award of Master of Philosophy (M.Phil) to the Dublin Institute of Technology 2002.


The objective of the M. Phil degree project was to improve the digital acquisition speed of the existing Ocean Optic I/O S1000 spectrometer system. Research carried out prior to this research work indicated that the existing system, although allowing for successful spectroscopic measurements, did not provide for a true time-base required for time-resolved spectroscopy. The analogue/digital speed aspects of the I/O were investigated and shortcomings were found in the digital I/O of the system. These shortcomings were investigated and the existing Ocean Optics software was found to have a considerable role in the lack of overall acquisition speed. Various Ocean Optics software were tested and the digital acquisition performance was observed to be worse for newer modern Windows based Ocean Optics software than the older DOS based Ocean Optics software. A novel approach based on interrupting control of the computer to concentrate maximum processor speed to acquire the digital I/O as fast as possible was embarked upon. The approach allowed real-time analogue signals to be digitally converted and acquired to computer memory. Based upon these real-time speeds, a real-time digital acquisition system to control the S1000 spectrometer I/O system was designed and tested out in the graphical user-friendly LabVIEW environment. These tests showed that the interrupt based digital acquisition system allowed novel optimum time-resolved spectroscopic measurements to be carried out.