CURRENT STATUS OF DIII-D PLASMA CONTORL SYSTEM COMPUTER UPGADES

OAK-B135 This paper presents the latest status of the DIII-D Real-Time Digital Plasma Control System (PCS). The primary focus will be on the new computing and data acquisition hardware recently incorporated into the PCS and the added features provided by the new hardware. The upgrade of the PCS real-time computing and data acquisition hardware has been in progress for the past three and a half years. Since the initial proposal to migrate off the old VME i860 based system to more modern computing hardware, the PCS has seen a number of changes and improvements occurring in several planned phases. The final phase of the upgrade was successfully completed earlier this year. This phase included the complete removal of the i860 computers and Traq digitizer hardware and the incorporation of high performance Intel PCI based computers fitted with 32 Channel PCI digitizers from D-TACQ corporation. Distinguishing features of the completed PCS upgrade include a custom real-time data acquisition and control solution based on the Linux Intel computing platform and a scaleable multi CPU parallel processing architecture connected by a 2 gigabit per second Myrinet network. Among the many improvements resulting from the upgrade are the higher computing performance (factor 20 over the previous system), connectivity to remote DIII-D diagnostics through Myrinet fiber optic links and plasma diagnostic data displayed in real-time on digital oscilloscopes