Design And Implementation Of Parallel System For Data Acquisition Based On Embedded Linux

Large format scanner, which is a kind of image input device that meets the special needs of users, should possess the general features of large format and high resolution of more than 600DPI. Most of the large format scanners are designed with the multi-CCD technology. In the past for domestic design, sampling modules of the several CCDs finish sampling work of a line one after another; this constrains the scanning speed and can not satisfy the actual needs. So it is of great practical significance to design a new plan to enhance the scanning speed.A multi-CCD data acquisition system based on embedded Linux is built in this thesis. Of the factors that impact scanning speed of the scanner, the transmission speed through USB protocol and TCP/IP are not the key ones. It is the sampling speed of the several CCDs and the cooperative work between CCDs that determine the final speed of scanning. This thesis introduces an optimal method using multi-thread technology for parallel design. Several threads will be created to respectively response the image acquisition work of every CCD; in this way, times of sample data can be gotten than single CCD, which can increase the scanning speed fundamentally. Finally, high-speed feature of the new-designed multi-CCD scanner data acquisition system are confirmed through experimentation, which proves the feasibility and accuracy of the multi-thread design method in the high-speed data acquisition system.