VAX-based realtime data acquisition for scientific measurements

The criteria for recording laboratory data vary, depending upon the nature of the experiment. The I/O resolution, data throughput, computer processing power, and the RAM and disk memory requirements must be considered. This paper discusses the realtime system alternatives for data acquisition based on VAX/VMS computers. Specifically, the authors detail the hardware and software options available for converting, processing, storing, and displaying realtime experimental data. Realtime data acquisition and control I/O systems conforming to IEEE Standard 583 (CAMAC) are discussed and their characteristics are detailed. The CAMAC systems exhibit high data throughput and multichannel capability. Even distributed CAMAC systems exhibit high I/O throughput. Finally, they describe the VAXlab Software Library and the Realtime Calling Standard as solutions for the software problems typically encountered in research laboratories