INTELLIGENT CRATE CONTROLLER FOR THE SMALL COMPUTER SYSTEM INTERFACE BUS

THE CAMAC SYSTEM (COMPUTER AUTOMATED MEASUREMENT AND CONTROL) IS A COLLECTION OF STANDARDIZED MODULAR COMPONENTS WIDELY USED TO COLLECT DATA FROM PHYSICS EXPERIMENTS; IT HAS ALSO FOUND APPLICATION IN PROCESS CONTROL AND INDUSTRIALAUTOMATION. UNFORTUNATELY, THE CAMAC BRANCH HIGHWAY, THE PARALLEL DATA BUS USED TO CONNECT CAMAC CRATES TO THE CONTROLLING COMPUTER, IS EXPENSIVE DUE TO THE HIGH COST OF THE CABLE AND CONNECTORS PRESCRIBED BY THE CAMAC STANDARD. THIS SYSTEM COST IS FURTHER ELEVATED BECAUSE THE BRANCH HIGHWAY MUST BE INTERFACED TO THE COMPUTER'S BUS BY A SPECIAL DEVICE (THE BRANCH DRIVER) THAT IS PRODUCED IN SMALLVOLUME. DRIVERS ARE AVAILABLE FOR ONLY A FRACTION OF THE COMPUTERS CURRENTLY AVAILABLE. THESE FACTORS HAVE COMBINED TO DISCOURAGE INDUSTRIAL APPLICATIONS OF CAMAC, AND TO RAISETHE COST OF PHYSICS EXPERIMENTS. THERE IS, HOWEVER, A VAST ARRAY OF CAMAC DATA ACQUISITION MODULES AVAILABLE WORLD-WIDE, WHOSE USE WOULD BE FACILITATED BY A LESS EXPENSIVE INTERCONNECTION BUS THAT COULD BE INTERFACED CHEAPLY TO THE MORE COMMON PERSONAL COMPUTERS AND WORKSTATIONS. SUCH AN INTERCONNECTION COULD BE PROVIDED BY THE ANSI STANDARD SMALL COMPUTER SYSTEM INTERFACE (SCSI) BUS. THIS BUS IS APPROXIMATELY TWICE AS FAST AS THE BRANCH HIGHWAY. SINCE IT IS A WIDELY USED STANDARD FOR MASS STORAGE DEVICES, LOW COST INTERFACES ARE READILY AVAILABLE FOR NUMEROUS PERSONAL COMPUTERS AND WORKSTATIONS. THE SCSI BUS PROTOCOL IS MOST EFFICIENT WHEN USED WITH INTELLIGENT PERIPHERALS. PHASE I WILL INVESTIGATE THE DESIGN OF AN INTELLIGENT CAMAC CRATE CONTROLLER THAT WILL COUPLE THE CAMAC DATAWAY TO THE SCSI BUS. PARTICULAR ATTENTION WILL BE GIVEN TO INCORPORATING A LIST MODE OF OPERATION, SO THAT THE CONTROLLER WILL PERFORM A PREDETERMINED SEQUENCE OF CAMAC OPERATIONS IN RESPONSE TO A HARDWARE TRIGGER SIGNAL.