A Remotely Controlled Experiment System
Wei-Ming Ni, Zhu Liu, Jing Li, Song-You Wang, Xiao-Song Zhu, Yun-Sheng Ma, Jian Miao,
and Liang-Yao Chen
School of Information Science and Engineering, Fudan university
Shanghai Research Center for the Applied Physics
Ying-Wen Cai
School of Material Science, Shanghai Jiao-Tong University
Abstract
A method is proposed to provide a remote experiment system environment. The main task is
to develop the framework software that can be used to remotely control the experiment system.
The method has been applied to an advanced infrared spectroscopic ellipsometer to test the
principle. The system includes the local server and remote client, in a test connection. In
communication with the local operator as needed, the remote experimenter can adjust the
experiment parameters, in this case the photon energy range and the incident angle, to run the
system. When the experiment is over, the remote experimenter can immediately obtain the result.
Also, a visual monitoring system is set up to enable the remote user to watch the experiment when
the system is running. An improved methodology, based on a Web interface for more user friendly
and flexible use, is proposed for future development.
Keywords : Person-to-equipment; remote control; infrared ellipsometer.
I.
Introduction
The fast development of the modern information technology has deeply changed the life of
societies and people. One of the significant areas of progress worldwide is the wide use of modern
computer technology in broadband networks, resulting in a rapid growth of Internet applications.
This provides a major opportunity for future research and education and will substantially reduce
the distance limitation in traditional education. Scientists can realize research cooperation by
sharing experimental resources and systems through the Internet.
New methods and tools for this purpose provide an easier way for scientists to do research,
even in different countries, and will save experimental costs, especially for the scientists working
in developing countries. The remotely controlled experiment system also can be applied to the
education and distance learning process.
For the present study, an advanced infrared ellipsometer was used in the remotely
controlled system. We will discuss the method and software used to run the system with success.
The method was tested and realized in a real situation to remotely control the experiment through
an advanced optical network.
In the remotely controlled infrared ellipsometer experiment system, the client, i.e. the remote
operator, can adjust the experiment parameters, in this case the range of wave numbers or the
range of incident angles. During the experiment, the connection to other clients is blocked. For
security considerations, in order to protect the expensive experiment, protective methods such
one-to-one connection and password-setting were used. Moreover, the local operation running on
the server machine has an independent protection.
There are two functions in a remotely controlled system. One is called P-to-E (person to
equipment) function which is the principal subject of this paper while the other is P-to-P (person
to person) function. The P-to-E function provides shared tools to allow the remote client run the
equipment through the Internet. The P-to-P function involves another kind of shared tools to
enable the remote client to communicate personally with the local operator through the Internet.
The remote client, therefore, can be informed about the experimental process, and will understand
what is happening in the experiment.
II. Infrared ellipsometer system
The infrared spectroscopic ellipsometer is useful for many research projects for example in
physics, materials science, biology, medicine, and atmospheric science. From the infrared
spectrum data of the materials, the optical properties of the materials and other structure can be
obtained. This is a non-destructive optical measurement method with greatest advantages in
biological sample testing and photonic device studies. The instrument will also be used as a
powerful tool in the infrared beam line that will be established in the Shanghai Synchrotron
Radiation center in the near future.
The double-Fourier transform infrared spectroscopic ellipsometer was constructed in the
authors’ laboratory. The experiment system is controlled by a computer. The user can input two
parameters in the experiment, i.e., the wave number range from 2100 to 10,000 cm-1 and the
incident angle scanned from 30 to 90 degrees. The software was written by using the Microsoft
Visual Basic 3.0. The experiment scheme is shown in Fig.1.
1.Polarizer 2. Analyzer 3. Step-Motor 4. Detector Rotaing Table 5. Sample
Rotating Table 6. Sample Support 7. Plane Mirror
Fig.1 The optical and control system scheme of the Double-Fourier Transform
Infrared Spectroscopic Ellipsometer
III. The remotely controlled system
The remotely controlled system includes two components as shown in Fig. 2: one is the
remote client, the other is the local server. The two components have different functions. At the
remote client, the operator can set the experiment parameters and remotely watch and control the
experimental process, through an on-site video camera, and at the same time obtain the
Server
Internet
Client
Experiment
System
Control
Plane
Decoder
Image Capture
Video
Camera
Fig. 2 The remote control system scheme
Fig.3. The structure scheme of the remotely controlled system
experimental data. For the local server system, there are three main parts: 1. the infrared
ellipsometer experiment sub-system; 2. the server with control programs; 3. the video monitoring
camera system.
The communication system includes a computer that connects the remote client through the
Internet and the local server computer linking to the Internet, video camera, A/D decoder and
multi-dimensional rotating table.
P-to-E means person to equipment, which implies communication between two agents: the
person who will run the system, and the equipment. For the "person part", the operator will have
individual experiment requirements. Taking the equipment into consideration, there will be two
key software choices. One is the operating system, such as the Windows or UNIX systems that are
popular today. In the study, we have used the Windows operating system to test the system. The
other choice concerns the design of the software to control the equipment which was written in
Visual Basic, Visual C++, and Turbo C.
The ISA control software was written in the Microsoft Visual C6.0++ language. It
communicates with the experiment program by the method of translating and transferring the
Windows message. Therefore, the remote client should have the Microsoft Spy++ Tool, which can
capture the Windows message and transfer the information into the control program.
The real control system and operation menu are shown in Figs. 5-8. In 2001, the method was
tested with success in a real situation to remotely control the infrared spectroscopic ellipsometer
through an advanced optical-network across the city of Shanghai.
Fig. 5. Remotely controlled infrared spectroscopic ellipsometer
Fig. 6. Remote experiment system monitor
Fig. 7. Remote operation menu and monitor window viewing the experiment situation
Fig. 8. Remote operation menu and monitor window viewing the sample-mounting situation
IV. The HTTP server extension approach
In order to make the remote control environment process more flexible and user friendly, we
propose a framework software approach for future development. In this approach, the construction
of the remote experiment system is based on the HTTP communication protocol. All experiment
commands (including the setting of parameters and the execution of operations) are sent as HTTP
requests. After the HTTP server receives the request signal, the operation information is extracted
from the request string and then transferred to the experiment control process by IPC (InterProcess
Communication). The HTTP server software (Internet Information Server, Apache, etc.) must be
selected: here the IIS (Internet Information Server) has been chosen. The operational principle is
presented in the diagram in Fig. 4.
Use of the Web presents several advantages. First, Internet Explorer is a well-developed
interface tool for the client computer which is convenient and easily operated. Moreover, this
method faciliates the realization of a generally applicable remotely-controlled experiment system.
Our HTTP-based Server program links to the client by requesting, translating and transferring
command strings.
With respect to the experimental equipment, the sequence of operations is different. For the
proper action of the experiment system, the commands and experimental parameter settings
should be predefined in a data structure such as the following:
Type def struct {
LPSTR Name, Value, Description;
BOOL Required;
BOOL Valid;
} FormField;
where, Name is the name denoting a command and associated parameter set of the experiment;
Value is the value of the parameter set; Description is the description of the command and
parameters; Required=TRUE indicates that parameters of the experiment should be set, otherwise
they are ignored. Valid indicates the validity of the parameters of the experiment; if the
HTTP-based Server finds the setting of the experimental parameters by the remote client to be
invalid, it will send a error message to the client by calling an error information program.
Conveniently, to use the different experimental devices, users need only modify the
corresponding content of the command form and need not change the overall Server program for
the application. Following is the example to explain the process.
To take account of the variety of situations and instruments which can be used in an
experiment, the communication between the server and experiment program may differ. For
example, Windows Message Queue, Winsocket, Windows DDE (Dynamic Data Exchange), or
Named Pipe may be used to provide the interface port for IPC (InterProcess Communication) for
the Server program. One can select the IPC method by modifying an "*.ini" file. For example, for
the Windows Message method, the first parameter in the ini file would be specified as "Windows
Message", followed by the information to control the experiment, such as the title of control
program window or ID button of the control software, and the experimental parameters and
equipment commands. When one runs the HTTP server extension program, the program will read
the ini file first and then execute the operation. Therefore, the HTTP server extension program
functions as an intermediary which communicates between the client by and the experiment
control program, performing double translations between the communication protocol (HTTP) and
the "non-communication" protocol of the instrument. By careful design of a Web page, one can
use the same remote control interface to run several experimental devices.
The remote control process works as follows (please refer to Fig. 4):
1. According to the input requirements for experiment control presented in Web pages, the
"get" or "post" method is used to send to the server the parameters to be set in the experiment.
2. The ISA (International Server Associate) acts as a middleware. It extracts the client request
message first and then communicates with the experiment control process by IPC (InterProcess
Communication). Different methods can be used as IPC as explained above (the functional part of
this process is enclosed in red dashed rectangle in Fig. 4).
3. The experiment control software receives the message to control the system and translates
the message to the appropriate data format for the equipment, or just simply executes the
corresponding process in the software to control the instrument.
ISAPI Filter
www client
WWW
IIS
Experiment
IPC
ISA
Control
Figure 4. The Principle of HTTP Server Extension
An example of a Web based user interface in such a scheme is shown below:
Save File Name:
Rotate(2-10):
Incident Angle(0-90):
Wave Number Range (2100-10000)cm
-1
Setting
DataProcess
Html page source code:
<HTML>
<BODY>
<H1><B>Remote Experiment Sample</B></H1>
<FORM
id=FORMSETTING
title="Experiment
Parameter
Setting:"
name=FORM1
action
=
/scripts/Samples/RemoteCtrl_ISA.dll method="get" style="BACKGROUND-COLOR: gray">
<P>&nbsp;&nbsp;Save
File
Name:<INPUT
id=TextSaveFName
style="LEFT:
53px;
TOP:
54px"
name=FName></P>
<P>&nbsp;&nbsp;Rotate(2-10):<INPUT id=TextRotate style="LEFT: 52px; TOP: 97px" name=Rotate></P>
<P>&nbsp;&nbsp;Incident Angle(0-90):<INPUT id=TextAngle name=Angle></P>
<P>&nbsp;&nbsp;Wave Number Range (2100-10000)cm<SUP>-1</SUP> </P>
<P>&nbsp;&nbsp;&nbsp;&nbsp;<INPUT
id=SubmitSetting
type=submit
value=Setting
name=SubmitSetting title="" style="LEFT: 10px; TOP: 289px"></P>
</FORM>
<FORM
id=EXEC
title="Experiment
process:"
name=FORM2
action=/scripts/RemoteExec_ISA.dll
method="get">
<P>&nbsp;&nbsp;&nbsp;&nbsp;<INPUT
id=SubmitExec
title="DataProcess"
type=submit
value=DataProcess name=Ctrl_Proc></P>
</FORM>
</BODY>
</HTML>
In the above HTML code, the words in blue are the HTML language expressions.
When enters the experimental parameters (only the rotation angle and incident angle fields
are active on this sample page; in the actual interface, the user will also be able to choose the wave
number range) and save file name, and then clicks on the "Setting" button, the requested
parameters are sent by HTTP to the IIS Server program. called RemoteCtrl_ISA.dl to deal with the
request. This is done by sending a request string such as the following to the local server:
Get /scripts/samples/RemoteCtrl_ISA.dll ? FName=D:\\Data & Rotate=%2 & Angle=%70…
The ISA process "RemoteCtrl_ISA.dll" will then extract the data from the request string, and save
them to the array data base with the data structure described above. Clicking on the "DataProcess"
button will send the extracted message to the experiment control software through the
RemoteExec_ISA.dll program on the server.
At the local server end, one of the following systems are required:
 Windows NT Workstation, version 3.51 or higher, with Peer Web Server
or

Windows NT Server version 3.51 or higher, with IIS (Internet Information Service)
Acknowledgement
This work was supported by the UNESCO and the Ministry of Education of China.
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