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VIRTUAL REMOTE MEASUREMENT OF CONTROLLED SOURCES Authors: Florin SANDU, Gheorghe SCUTARU, Ioan Emilian CUCERZAN, Daniel IOLU
VIRTUAL REMOTE MEASUREMENT OF CONTROLLED SOURCES
Authors:
Florin SANDU, Gheorghe SCUTARU,
Ioan Emilian CUCERZAN, Daniel IOLU
Application Idea
„Leonardo da Vinci” Pilot Program RO/01/B/F/PP141024 “Virtual Electro-Lab”
The main goal of the program is the Internet publication not only of information but also of experimental resources
A client – server application to ensure remote and virtual measurement
Application Structure Client
Web Browser Html pages and Flash movies for stimuli submission and
results display
Server Web Server
PHP used to pass stimuli from the client to the server Workbench Server
LabView used to process stimuli, to perform the measurement and to create different formats of results
PSpice used for circuit simulation
Application Architecture
Client Web Server
Workbench Server
Internet
LAN
IBM PC Web browser Flash 5 plug-in
ACPI Multiprocessor PC MS Windows 2000 IIS Server PHP 4
Pentium PC with AT MIO 16E10 acquisition board
MS Windows 2000 LabView PSpice
WEB Application Interface
“hyper-schematic” where the user can directly change parameters
the node voltages (the student can notice the correct Bias-Point of the BJT)
factor divider current of inverse
3R
3R2R1R
1RI AC
1G inV c
I AC
plot of the
Application’s VI
First frame of the VI, containing a wait – loop
Application’s VI
Variables' extraction from the stimuli file and
construct of the “.cir” file
Application’s VI
Frame for the “System-Exec” sub-VI
Application’s VI
Frame 4 of the VI, containing the construction of the“op3_val.txt” file, the graphics arrays construction and the copy of op3.out from the work-bench to server
Application’s VI
Graphics plot and image-to-file save frame
Flash 5 advantages
Vector graphics Easy to use editing environment Scripting language(“ActionScript”)
Movie control gotoAndPlay gotoAndStop stop
Communication capabilities LoadVariablesNum GetURL
The structure of our interface
1 scene
3 layers
4 frames
PHP structure <?php
//gets all variables from swf file
$r2 = $HTTP_POST_VARS['r2'];
$r3 = $HTTP_POST_VARS['r3'];
$r4 = $HTTP_POST_VARS['r4'];
$r5 = $HTTP_POST_VARS['r5'];
$r6 = $HTTP_POST_VARS['r6'];
$c1 = $HTTP_POST_VARS['c1'];
$c2 = $HTTP_POST_VARS['c2'];
$c3 = $HTTP_POST_VARS['c3'];
$v2 = $HTTP_POST_VARS['v2'];
//create and open the output file
$filename="./values.txt";
if (!file_exists($filename)) {
touch($filename); // Create blank file
chmod($filename,0666);
}
$f=fopen($filename,"w");
//writes the input values in file "values.txt"
fputs($f,"R2:".$r2."\n");
fputs($f,"R3:".$r3."\n");
fputs($f,"R4:".$r4."\n");
fputs($f,"R5:".$r5."\n");
fputs($f,"R6:".$r6."\n");
fputs($f,"C1:".$c1."\n");
fputs($f,"C2:".$c2."\n");
fputs($f,"C3:".$c3."\n");
fputs($f,"V2:".$v2."\n");
fclose($f);
?>
Practical student works
The display of node voltages
Practical student works
The gain plot
Practical student works
Cuasi-open loop gain as reference for auxiliary graphical construction
VCCS Application Interface
Text boxes for numerical submission (with default values)
VCCS Application Interface
IC vs frequency simulated characteristic
CCCS Application Interface
Text boxes for numerical submission (with default values)
CCCS Application Interface
The display of node voltages
CCCS Application Interface
IC vs frequency simulated characteristic
CCVS Application Interface
The display of node voltages
CCVS Application Interface
Gain vs. frequency simulated characteristic
Conclusions
The integrated LabView work-bench server provides robust equipment control and direct Intranet communication with the server
The “wysiwyg” remote testing, combined with complete PSpice simulation and theoretical computation has a great educational impact
The results can be extended to electro-mechanical automation & robotics, with an implementation that should also include virtual reality
