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Computer Systems

The National Synchrotron Light Source facility at the Brookhaven National Laboratory in New York, consists of two storage rings, one for VUV operating at 800 Mev and one for XRAY at 2.8 Gev and a common injection system comprised of a linear accelerator and a Booster ring.

Hardware Architecture

The hardware architecture of the present control system follows the current trend seen in many accelerator facilities. It is a two-level distributed system consisting of HP/900 series workstations connected by the standard ethernet to VME-based microprocessor subsystems. All the workstations have local disk and sufficient memory for fast response. Workstations are used as file server, back-up file server and for program development and other miscellaneous functions. A few Xterminals and PC workstations with Xterm software are located around the ring close to the hardware to provide support to engineering staff. The application programs can be run from any workstation. Uninterruptible power supplies are provided for key systems. The control room stations and the VME micros are connected by a real-time ethernet subnet. The private NSLS subnet and the beam line users subnet are connected via bridges and routers to the real-time subnet, thereby keeping the building traffic off the real-time network. There are approximately seventy VME microsystems for controlling and monitoring the machine hardware.

Software Architecture

The host level application and modeling programs use X11 and Motif based graphical and textual interfaces. The hardware control and data access by the application programs have been simplified by the high level interface libraries. which are responsible for transmission of commands/data requests, data retrieval etc. At the lower level, the monitor software provides the communication interface to the workstation programs and the hardware equipment.