Implementation and operation of VAX-based data acquisition system for the large coil task

The VAX-based data acquisition system for the International Fusion Superconducting Magnet Test Facility (IFSMTF) at Oak Ridge National Laboratory (ORNL) is a second generation system that evolved from a PDP-11/60-based system used in the two-coil test and facility shakedown. The VAX 11/780 processor has been interfaced through a CAMAC fiber-optic byte serial highway to five existing LSI-11/23 frontend processors through dataway access port (DAP) modules. The VAX CAMAC interface has permitted the addition of analog input channels for the refrigeration system and analog and digital outputs to drive display devices. Software utilities are provided to operate the data acquisition hardware, maintain data base files, and display data. Graphical display of data is accomplished through the use of VAX IDL (Interactive Data Language), which provides device-independent data presentation. Output from IDL is available for Tektronix displays and has been extended to generate TKF and Versaplot graphics metafiles for hardcopy output to Versatec printer/plotters. In addition, a Sension display system is available for graphical display of real-time data in the form of strip chart and tabular displays. This paper describes the hardware and software design of the system and the operation of the system during the full-array testing sequence.