Research on transparent access method for multiple types of data acquisition device in EAST PCS

With the development of EAST physics experiment, more and more diagnostic signals need to be acquired in realtime for advanced plasma control. Different types of data acquisition devices with suitable sampling rate need to be deployed nearby the diagnostic signals because of the distributed characteristics of diagnostic systems. To obtain these distributed signals effectively and provide a transparent access to multi-type data sources for the control algorithms in the plasma control system (PCS), a deployment specification for standard acquisition cabinet and the transparent access middle layer with device virtualization technology are designed and implemented. The reflective memory (RFM) high-speed network is selected to realize data communication between distributed data acquisition cabinet and PCS. For the transparent access middle layer, a mapping file for the diagnostic signal names and the channels of specific data acquisition device, as well as a set of data transmission specifications between the PCS and distributed data acquisition cabinets, is defined. This transparent access method shields the differences of peripheral devices and provides a specification to expand multiple types of data acquisition devices flexibly. Based on the aforementioned design principle, two sets of acquisition devices, which have higher acquisition performance and low latency, are successfully integrated to the distributed systems.

Automated summary

In order to effectively acquire distributed diagnostic signals and provide transparent access for the plasma control system, a deployment specification for standard acquisition cabinet and a transparent access middle layer have been designed.