The SSCL LINAC control system

The SSCL Global Accelerator Control System (GACS) is a standard multi-layered system. Six levels of functional hierarchy are used to specify and describe the GACS. Level 6 provides information exchange services. No true control functions are performed at this level. This level is used to provide a pathway for the exchange of information between the Control System and SSCL computer services. Level 5 is the machine integration level of the system. At this level, controls for all SSCL machines, i.e., LINAC, LEB, MEB, HEB and Collider, are integrated into a single unit. This level includes a central control room for operations. Level 4 is the machine control level. At this level all module level controls are integrated into an SSCL machine, in this case the LINAC. Level 3 is the LINAC module controls. The function of Level 3 is to tie the various subsystem controls together into stand-alone modules, i.e., Ion Source, RFQ, etc. Level 2 controls are defined as those which logically combine a group of front-end systems into a control unit. Subsystem controls such as vacuum and RF are performed at this level. Level 1 is the front-end controls. This level provides interconnections between sensors and controls, signal conditioning, I/O module interfaces, front-end processors and local operator stations used for system maintenance and commissioning