PADAC Multi-Microcomputers Basic Building Blocks for Future Control Systems

Based on experience with the PETRA control system a concent for multi-microcomputer arrangements within the PADAC standard has been developed. This setup allows the use of independent microcomputers (based on the TMS 9900) within a group of PADAC crates. Each individual microcomputer executes code from its local memory and has access to all PADAC I/O modules and a common database (256 kbytes of memory) via the shared PADAC bus. The database is assumed to contain at any time the current status of a certain control sub process. A modified version of the SEDAC data acquisition hardware is be used to collect the process status at the necessary refresh rate. The communication with the outside world (operator console, etc.) is accomplished by a fast packet switching network (FPSS3).