Multi-Processor Control of the 100 KeV McMaster Mark IV Sputter Ion Source

An ion source control system has been developed to provide 100 KeV heavy ion injection into the McMaster FN Tandem. The control system is composed of a CMOS RCA1802 microprocessor at deck potential which conveys power supply command/status data from/to a PDP-11/23 via fibre optic link. Approximately 50 fail safe interlock conditions are maintained by the PDP with capabilities to shut down affected power supplies if interlock states warrant. There are commands that allow operator intervention to set supply voltages, source cone position, and interlock bypass. Power supply set point voltages are either maintained to within modifiable regulation windows, or set to track manually controllable shaft encoders. The ion source status is provided to the operator from the PDP via a DEC VT220 monochrome display terminal and printer. There are two possible display modes, both with variable updates rates; one involving power supply voltage/current information and interlock status, and one indicating abnormal stati caused by cascading failed interlocks. An additional serial line on the PDP-11/23 allows user communications, including a "screen dump" of any of the displays, to a remote location through the use of a 1200 baud modem.