Equipment control and computer interfacing using LabVIEW
This thesis describes two control projects undertaken at the Maddox Laboratory of the Texas Tech University. The first project concerns digital image data acquisition from a CCD chip into a PC. The second project deals with the control of a Magnetron Sputtering equipment and its accessories. Both the projects culminate to working LabVIEW programs that automate the controls for both the systems.
CCD sensors can be classified broadly into two categories - the linear sensors and the area sensors. The sensor used in the data acquisition project was an area sensor of the "full-frame" type. A matrix of photo-ensitive CCD pixels generate electron packets of varying charge content that is proportional to the amount of incident photons. After a finite integration period, during which photo-generated electronic charges accumulate within the potential well of each CCD photo-site, the whole field of pixels is shifted towards the output node. This shift towards the output node occurs in several steps. First, a Vertical shift clock pulse causes all the rows to be shifted downwards by one position -resulting into the bottom row being shifted to a serial shift register. A series of, Horizontal-Shift clock pulses then shift out the pixels one by one through the shift register into the output diffusion node. The output diffusion is voltage modulated by the charge content in a pixel. This voltage is sensed by an output buffer amplifier. After all the pixels in a row have been shifted out to the floating diffusion at the output and sensed by the output amplifier, a row shift occurs again and the same sequence is repeated.