| The automatic screen printing machine discussed in this thesis is based on thearchitecture of open CNC system. PC with real time operation system is adopted as high-levelsystem control plan, while motion control cards with flexibility and scalability are used aslow-level system control scheme. Software and hardware design of automatic screen printingmachine based on this architecture will be mainly discussed. The following contents areincluded in this thesis:In the first place, by analyzing the development tendency and working flow of automaticscreen printing machine, pc+motion control cards are adopted as control structure scheme.The real-time and reliability of control data transfer are guaranteed by PC with linux real-timeoperation system and mention control cards with motion output and communication interfacebetween PC and mention control card. The scalability of system is guaranteed by lowercomputer fiber loop architecture.In the second place, the low-level software and hardware design are introduced in detail.The schedule of hardware design, communication realization between upper computer andlower computer, the design of lower computer and driver design are discussed. ATLRA seriesFPGA which commonly used in digital communications is adopted as core chip of motioncontrol card, while VHDL is adopted as programming language. The functions of the masternode, namely the main station of fiber-loop, of loop architecture include PCI-E busconversion, PCI protocol realization, output commands receiving and commands to propercontrol nodes transferring. The functions of salve node, namely the vice station of fiber-loop,of loop architecture include commands data receiving from master node, data conversion toproper axis and output switch, and data transferring of salve node to master node. The printingfunction of automatic screen printing machine is realized by lower computer. The real-timeand accuracy of this system are also guaranteed by this architecture.In the last place, the software and hardware of low-level and high-level are connected.The testing result of automatic screen printing machine is presented. |
