Software architecture of the longitudinal feedback system for PEP-II, ALS and DAΦNE

We describe the software architecture of the Longitudinal Feedback System being built for the PEP-II B-Factory at SLAG, the ALS light source at LBL and the DA/spl Phi/NE phi factory at Frascati. This VME/VXI based system utilizes commercially available embedded CPU controller boards running the VxWorks real time operating system. The operator interface for PEP-II and ALS is based on the EPICS control system package. Embedded processors are used to load, monitor and diagnose various components of the system. The feedback function is implemented using digital filtering techniques on a DSP farm residing in the VME crates. The operator interface is written to allow the loading of applications, e.g., accelerator diagnostic functions, system hardware integrity functions, etc., without intervening controller reboots.