The NSTX-U Digital Coil Protection System Autotester

Abstract

Included in the Upgrade to NSTX at Princeton University's Plasma Physics Laboratory, is the development of a Digital Coil Protection System (DCPS). This real-time system is the primary protection for the machine coils and structure of the NSTX-U vessel. A requirement for a means to thoroughly test the DCPS birthed the Digital Coil Protection System Autotester (AT). From its inception in May of 2013, the purpose of the DCPS Autotester system was to provide the user a means by which to send a pre-configured set of waveforms to the DCPS for the purpose of testing the functionality of the system. The output data stream consists of 64 analog outputs and 32 digital outputs at a rate of 5k samples per second. The AT monitors 32 digital inputs coming back from the real-time system. It logs all data sent to the system and the outputs from the system during each test cycle. The AT application, written using National Instruments LabVIEW 2013, can be run stand-alone or synchronized with the central NSTX-U Facility Clock (cycle). The AT also provides a continuous sample clock, which is required by the real-time system, whether or not the Autotester software is running. Although the Autotester was developed for the single purpose of certifying the DCPS system, it has grown in purpose. Recently, it has been used to test and validate the NSTX-U Power Supply Real Time Control system. Plans call for using it to verify new systems such as the Plasma Current Calculator and Permissive Generator which are relevant to Day 1 NSTX-U operations.