Design and construction of the Advanced Photon Source 352-MHz RF system switching control

A switching control system has been designed and built to provide the capability of rapidly switching the waveguide and low-level cabling between different klystrons to operate the Advanced Photon Source storage ring in the event of a failure of a klystron system or to perform necessary repairs and preventative maintenance. The twelve possible modes of operation allow for complete redundancy of the booster synchrotron RF system and either a maximum of two storage ring RF systems to be completely off-line or one system to be used as a power source for an RF test stand. A programmable controller is used to send commands to intermediate control panels which interface to WR2300 waveguide switches and phase shifters, RF cavity interlock and low-level RF distribution systems, and klystron power supply controls for rapid reconfiguration of the RF systems in response to a mode-selection command. Mode selection is a local manual operation using a keyswitch arrangement which prevents more than one mode from being selected at a time. The programmable controller also monitors for hardware malfunction and guards against "hot-switching" of the RF systems. The RF switching control system is monitored via the Experimental Physics and Industrial Control System (EPICS) for remote system status check.