Development of a prototype time synchronization system for KSTAR with a VME–bus system

The time synchronization system (TSS) for KSTAR has been devised and is under development to support steady-state real time control for discharge operation, plasma diagnostics, and collection of a huge amount of data. The purpose of the system is to provide synchronized operation of all experiments according to the reference scenario, universal time for all the tokomak systems and appropriate time-stamping on all acquired data and events. The central timing system and local timing units, which comprise the time synchronization system, are connected via the dedicated optical time network. The TSS communicates via the giga-bit machine network for the provision of universal time, and uses the shared memory-based real-time network for real-time feedback control. A prototype timing modules has been developed and tested, it is based on the VME–bus standard and uses FPGA and micro-processors to implement the major functions such as time decoding, a 64-bit time counter, data processing, clock/pulse generation, etc. We are testing the pilot timing system with central and local timing units, and operated in an EPICS environment, the middleware program of the KSTAR control system. This paper presents features of KSTAR timing system and details of the developed prototype timing modules.