Trigger and synchronizing system in PLS

The PLS consists of a storage ring and an injector linac. We had been built the timing system which allows the direct injection of e-bunches from the linac into the storage ring and feed the fiducial trigger at the pulsed devices. In order to allow a good reproduction of the fill pattern, a low jitter triggering electronics and a real-time computer control have been adapted. This electronics is based on the use of programmable preset counters synchronized by a clock thrived from the RF master oscillator. The circuits are implemented on several Euro-cards and programmed with an OS-9 real-time OS. It is also composed of a part of PLS control system. Ail trigger modules are fully controllable by the control system through VMEbus. Hence, any bunch of the storage ring is selectable and any fill pattern can also make with a good repeatability