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SST-1 Data Acquisition Group

Group Leader: H D Pujara(pujara at ipr.res.in )
Members of the Group

Main Objective

SST-1 Data Acquisition group is engaged in designing a High speed lossless data acquisition system for SST-1 diagnostics for a shot duration of 1000sec. The needs for steady state Tokamaks are for DAS is different compare to a Tokamaks used in pulse mode with a finite pulse durations. The steady state nature of operation has significant effect on instrumentation and specifically selection of digitizers, interface to host system and OS are the most crucial ones The system demands digitization of signals, online processing, viewing of data on network nodes and permanent storage for future retrieval. The volume of generated data is very large posing many technical challenges. Considering the technical aspects and needs of diagnostics, the plasma diagnostics are broadly divided into slow speed and fast speed diagnostics. All slow speed acquisition will be implemented on PXI based system. The PXI is a fast growing technology based on the industry standard PCI bus. The concept chosen for implementation permit host computer to be external to acquisition unit The acquisition unit is connected to host with 1.2Gbits/s fiber optic link. This allows one to take the benefits of growing technology and system performance enhances without any efforts. Over all the needs for about 200 channels of slow speed plasma diagnostics of continuous acquisition will be mate by PXI based system. For high peed diagnostics the CAMAC bus based instrumentation has been chosen. In pursuance acquisition at 1Mhz sampling and to archive self reliance in the area of CAMAC based data acquisition, efforts are being put for the developing CAMAC digitizers module supporting acquisition at 1MHz. The concept adopted here is segmentation of memory for capturing the signal on selected events. Considering the unique needs of high speed plasma diagnostics a 4 channel transient digitizer has been developed in house. In the area of CAMAC crate controller a crate controller has been developed. The crate controller is based on ISA bus supporting 16 bit transfers under programmed I/O mode and DMA. Under the DMA mode it supports a burst transfer at 2Mbyte/sec. The device driver has been written for WindowsNT, Windows2000 and Linux. All needs of fast diagnostics for about 400 channels will be mate by in-house developed CAMAC digitizer and Crate Controllers.

Current Activities

Currently following major activities are under process Development of Client/ Server based software package for data acquisitions in LabView and MSSQL Development of 4 channel CAMAC digitizer with 12 Bit resolution, 1MHz sampling rate and 512KB on board storage per channel Development of PXI based CAMAC Crate controller Development of Software for invoking CAMAC device driver in LabView