Process Controlling a Research Device

Operation of the new FM-1 research device at the Princeton University Plasma Physics Laboratory utilizes an IBM 1800 Process-Controller for numerous control functions and extensive status indications and annunciation. This was the first use of a process-controller as a full experiment controller at PPL. Practical experience was gained in the hardware and software characteristics of such a control system, as well as methods of documentation. An optimum allocation of storage exists for a system of this type. A minimum core of 16,000 16-bit words plus executive is also required. Permanent core is used for those programmed actions requiring rapid response and insuring safety to personnel or equipment. Exchangeable core is used for supplementary functions and startup-energize operations. Timing functions are affected by the cyclic updating of input and output data and methods were developed to compensate for this. Documentation provides duplication of program cards, listings and disks as means of backup. Program links, messages and designations are logged. The drafting system allows for more rapid design of new controls as well as changes to present ones.