Upgrading of the EAST Distributed Synchronization and Timing System

The present EAST Distributed Synchronization and Timing System (DSTS) provides synchronized sequential triggers and clocks for tokamak control and measurement. However, a more flexible and user-friendly DSTS is required to realize advanced plasma timing control. Central Timer Unit (CTU), Synchronized Local Timing Node (SLTN) and optical network composed a new DSTS. Based on embedded technology and Field Programmable Gate Array (FPGA), some philosophies are adopted in the upgrade of DSTS. Using SOPC (system on a programmable chip) technology, firmware and software design are implemented on a FPGA chip. The former solution of programmable chips cooperating with off-chip microcontrollers is replaced. Some new requirements, such as isolation & fan-out module, auto-diagnose malfunctioning delay, debugging in-a-key, new trigger output characteristics and user-friendly interface are integrated into SLTNs. The new DSTS is more suitable for the synchronization and timing control of the EAST fusion experiment. It is successfully operating since 2009 EAST experimental campaign.