Wide-Band Cable Systems at SLAC

Abstract

SLAC's first cable TV system was installed in 1979 to remotely monitor a narrow pulse generated in the west end of the klystron gallery. When Stanford Linear Collider (SLC) experimental work began at the west end of the accelerator this cable was upgraded to a bidirectional system. The present accelerator control system is based on a distributed processing configuration using a PDP11/780 VAX in the Main Control Center and Intel single-board computers in a multibus configuration along the accelerator. The high-speed data linking is supplied by a 1 MBaud Time Division Multiple Access Network. A midsplit configuration was chosen for the cable because it provides roughly equal spectra above and below the filter split. The cable will offer the following services when it is completely utilized: four 6 MHz video channels (camera or computer signals); forty channels of voice (CB sets for intercoms); two 6 MHz 1 MBaud channels (monitoring and control of the accelerator); one 6 MHz of Sytek System 20 9600 baud channels (terminal to VAX); and six 6 MHz point-to-point 2 MBaud channels (pattern and fast feedback loops). These subsystems and their interfaces are described and schematicized.