HT-7
ASIPP
The Distributing Control System
in HT-7 Tokamak
Zhenshan Ji, J.R.Luo, et al.
Institute of Plasma Physics, Chinese Academy of Sciences,
Hefei 23003l, P.R.China
telephone: +86-551-5591375, e-mail:[email protected]
Abstract
The Distributing Control System (DCS) has been successfully
upgraded on the HT-7 superconducting Tokamak, which includes
many subsystems. The basic unit of the DCS is the PC-based
industrial application and all the subsystems are equality for the
logic position, each subsystem completes the process with its'
control task. Using this structure, a complicated task will be
divided into many subtasks, which are the parallel running process,
and are controlled independently. As the distributing control
system, it is comprised with the many subsystems such as
programmable control; feedback control; monitor; data acquisition;
data saving; real time display and analysis, which are connected
by the network with the different computers of the HT-7 tokamak.
The Compose of the DCS in HT-7
•
•
•
•
•
•
(1)
(2)
(3)
(4)
(5)
(6)
The main control system
The poloidal field control system
The toroidal field control system
The gas injection control system
The synchronous timing system
Remote control system
The Compose of the DCS in HT-7 (2)
• (7) The data acquisition systems
• (8) Real time display system
• (9) Delphi 5.0 for interface with display the raw data in
real time
• (10) The data searching system is based on WWW, it
uses the Internet/Intranet technical and is based on the
Browser/Server mode to setup a distributed multi-user
system.
Fig. 1 The structure of the DCS in HT-7 Tokamak
The User Interface of the DCS
• The user interface for the main control system is a
important role for the operators, it should be easy to use.
• An example of the interface for the main control system is
shown in Fig.2.
• The operator can click the button to change the subsystem
parameters, just like the poloidal field system, gas
injection system, data acquisition system etc in the 30
seconds before the shot.
Fig. 2 The User Interface of the Main Control System
A Graphical User Interface For The
Poloidal Field Control
• For example when poloidal field button is clicked, the
interface of the poloidal field control system will be
displayed in a sub-window show in Fig.3:
Fig. 3 A Graphical User Interface for the poloidal field control
• If the operators want to change the values of the vertical field
angle, ohmic heating angle, plasma current, horizontal
displacement and vertical displacement, who only just click the
relevant button . The advantages of the DCS in HT-7 are as
follows:
• (1) To monitor the process in a real time during the experiment
• (2) To preset the control parameters to the subsystem
• (3) To provide an easy to use interface for the experiment
operators
• (4) To adjust the control parameters by the operators after each
shot in real time
• (5) To expand easily if there will be the new technology for the
system in the future
• (6) To transfer the data between the main control system to the
each subsystem with the fast Ethernet in order to control the
device running in a better case
The Plasma Density Feedback
Control Subsystem
• The plasma density feedback control subsystem (PDFCS) is
composed of many subtasks, such as data acquisition, handling and
sending out gas puffing control pulse to adjust the amount of gas
injected into the vacuum vessel of the equipment, in real-time.
• The previous PDFCS is based on Windows operation system. But it
still has some problems we can’t solution, because the problems are
brought by the windows platform based on we urgently demand
that the PDFCS can provide more real-time control process and
more excellent control results.
• In such background, we had been upgraded the PDFCS successfully.
Structure Of The Plasma Density
Feedback Control Subsystem
• The structure of PDFCS is designed to be an Up-Down
machine style.
• PID Controller Based on Neural Network Adapting
Regulation(NNAR)
• The Up machine bases on Windows operation system,
which can provide excellent man-machine interface that
makes parameters setting and data showing in graph and
text style very easy.
• The Down machine bases on VxWorks real time
operation system.
Compare Old PDFCS With New
PDFCS
Digitally-Synchronized Timing
System
• The timing is indispensable both for the control and data
acquisition in order to coordinate them to run synchronously on
the experiment standard timing.
• The synchronization system is based on VXI bus.
• There are two typical modules, one is for clock and other is for
trigger.
• The synchronization system provides master trigger signal to
separate data acquisition systems with uniform clocks and trigger
times.
• Optical fibers are used for the distribution linkage because they
provide the good accuracy of the transfer delay and electric isolate.
Their structure is showed Fig.1, and their basic specifications are as
follows:
Basic Specifications Of
Synchronized Timing System
• There is a 10 MHz crystal on the modules of
trigger and clock.
• Signal outputs can preprogrammed
• Optical fibers are used for the output linkage
• Delay trigger out covers hours-long operations
• System flexibility of expansion as VXI modules
Remove Control System
• As several different operating systems and collection
software are used in the distributed computers of the
HT7DAS, each subsystem should be setup respectively if
the parameters need to be modified. They are difficult to
control and maintain the HT7DAS.
• Remote cooperation and communion become more and
more important in the fusion experiment. So, it is
imperative to develop a central control system for
HT7DAS.
• Remote control for the parameter of the collection
subsystem demands to be realized .
The Principle of the RCS
The mixed model of Browser/Server and Client/Server
are adopted. Its principle is shown in Fig.4.
ASP ,Java and Visual C++
Fig.4 The principle of the RCS
The Structure Of The Data Acquisition Net
Fig. 5 The structure of the data acquisition net
Real Time Display and Real Time Data
Acquisition System Based on PCI Bus Technology
• Conventional data acquisition systems are often called as the batch-processing
ones, and usually they apply in short-pulse discharge experiments. As the postprocessing procedures after each discharge end, the date acquisition, storage,
and visualization have been sequentially executed for the diagnostic raw data
produced within digitizers.
• In the near future, we should hold the long-pulse experiments
whose duration will be up to several minutes, however, such a
post-processing mechanism has no effectiveness because people
cannot observe any diagnostic data during the discharge
continuation. Therefore, the real time data acquisition and
simultaneous display will be indispensable for the long pulse
experiments.
Real Time Display and Real Time Data
Acquisition System Based on PCI Bus Technology
• To satisfy requirements, real time display and real
time data acquisition system based on PCI bus
technology have been developed successfully.
• VxWorks real time operation system
• C environment, sockets for communications
• Easily transportable to other experiments
• PCI-PCI bridge transfer rate is 132MB/s
Network Communication System
• Two methods of communication have been used in
the communication
• File sharing
• Standard Sockets and Winsock program: the
standard Sockets and Winsock, which based on the
TCP/IP protocol of the Microsoft in the DCS,
program those communications.
• These programs are run under different operating
system such as windows, Linux, VxWorks ect.
Graphical User Interface For
Data Analysis
• The display and analysis of the
experiment results is carried out by
software named GT7(A windowbased graphical interfaces software
is designed by our institute using the
Delphi and Visual c++)
•
GT7 is not only restricted to the
simple display of collected results,
but it is also to use in conjunction
with data analysis tasks.
Fig. 7 A Basic Display for the
experiment results
SUMMARY
• The Distributing Control System (DCS) of the HT-7 Tokamak has
been successfully operated.
• The system is being up-graded to new modern hardware which is
modular and extensible.
• The software architecture contains a user-friendly GUI interface,
modern client-server architecture,scalable, parallel real time
computations and is primarily written in c(and Delphi for GUI)
• Many complex plasma control problems have been solved.
• It has proved stable and reliability
• All based on the PC technology.
Thanks!