Data acquisition and control using ETHERNET

We have developed a distributed computer control system to monitor and control a linear accelerator. This system consists of two PDP-11s and eight LSI 11/23s linked together with ETHERNET. The higher level systems (control consoles, etc.) use the RSX11M operating system, whereas the data acquisition and control is performed using the RSX11S operating system downline loaded from a central host computer. Locally written ETHERNET drivers are used to reduce the CPU overhead and therefore improve system response. The ETHERNET system permits remote file access by means of operator or program interaction, as well as supporting downline system loading. Control-system functions supported are supervisory control, closed-loop control, data monitoring, and data recording. 4 refs., 2 figs., 1 tab.