A dedicated multi-process controller for a LEP RF unit

The operation of each RF unit for the LEP (Large Electron Positron collider) requires that several control processes be run simultaneously. Local and remote access is required to around 2500 individual parameters and status indications inside the unit. Normal operation of the unit involves complex procedures requiring a considerable amount of sequential access equipment within the unit. Optimum performance and overall maintainability are achieved by calling up locally resident procedures. The needed surveillance and alarm monitoring can run locally, making a summary status available for the control center. The local process controller hardware is realized as a hybrid VME/G64 crate with a 68020 VME module as the main processor. Two 68000 VME slave processors having G64 ports handle communication with equipment buses. VME high-resolution graphics interfaces provide interactive local control via a touch screen and separate data display. A VME MIL-1553 interface provides the connection to the control system. Local control, remote control, and surveillance run concurrently on the main processor under the OS-9/68 K multitasking operating system