WiTAG system involved in education studies

Ramona – Georgiana Oros Material Engineering

Transilvania University of Brasov Brasov, Romania

oros_ramona@yahoo.com

Abstract — Considering the fact that specialized learning processes became an indispensable component in anyone's life regardless of age or domain, we realized that students may have access to equipments that can be really embedded in industrial environment. For this reason educational materials are not used only in academicals spaces but also in companies or others institutions. WiTag system is a small system that can be used in such way, educational and industrial. In this paper the educational part is going to be presented, the laboratory work around this device and also the research work. The WiTAG system can be controlled physical, by hand in the lab, and also remote over Internet.

Keywords-wireless sensors, remote control, WiTAG.

I. INTRODUCTION

In our days wireless technology is one of the new most important technologies used on the market. This technology is presented to students with all its aspect: equipments, transfer of information, connections with other equipments. One of the most important aspects refers to the transmission of data and information over distance. This information can be obtained from any kind of equipments through sensor or other systems that are connected to each others.

Wireless sensor represents one of the greatest challenges in wireless domain. Most of the sensors that are now on the market are not totally wireless. Wireless communication is realized only between the central point of information of measurement and/or processing and the user's PC. The relationship between measuring instruments and systems is done by wired connections as well as centralized data system.

The wireless sensor system that is presented in this paper, WiTAG system, is a complex one that is totally wireless, all data is transmitted from the sensor to an access point. This is a really new technology that students should know because in industrial domain such devices are used for automation of equipments.

II. WITAG SYSTEM

TAG4M represents the central part of the wireless sensor system, WiTAG system. This is an ultra-low power system that

has an internal processor, analog and digital inputs and outputs, sensors on board and can transmit wireless information trough an Access Point to a PC used as virtual instrument. The only requirements are to set a specific name and password for the router which should be the same as the TAG4M system has in its memory.

The core 32-bit processor runs on a 44 MHz external clock. Sensor measurement operation is controlled by an external 32 KHz oscillator. The CPU incorporates full 802.11 PHY, MAC and encryption engine.

The CPU has the follow internal elements:

80 Kbytes of RAM;

320 Kbytes of ROM that comes loaded with the following firmware components: boot loader;

eCos OS;

TCP/IP stack;

802.11b stack;

encryption and decryption support;

application/ deployment specific sensor drivers;

communication protocol;

power - saving support.

The most important characteristics of this device refer to the number of analogical and digital inputs and outputs that can be used for different measurements:

1 analog input of voltage (14 bits, 0 – 10 V);

3 analog inputs of voltage (14 bits, [-200mV; +500mV]);

1 analog input of current (4 – 20mA);

978-1-4673-2427-4/12/$31.00 ©2012 IEEE

4 digital outputs DIO;

1 sensor of temperature that is on board (thermistor 10K +/- 1C0);

Real-time clock for wakeup and time stamping.

Figure 1 The TAG4M system

The measurement capabilities are going to be explored by students during their laboratories, especially because this system can work as a part of cloud instrumentation. The measurements that can be done are: temperature, pressure, humidity, movement, sensor that gives out voltage in 0-10V or 0-0.4V range, sensor that gives out current in 4-20mA range.

This new and innovative idea of cloud instrumentation should be maxim explored by the students; in this way they can develop creativity regarding the connection of many sensors or equipments over the Internet.

III. EDUCATIONAL IMPLEMENTATION OF WITAG SYSTEM

Using the WiTAG system students have the possibility to

make physical or remote measurements. If the measurements are made in the lab they need a PC that has LabVIEW Software and the measurement applications installed on it. For distance measurement students need only Internet connection to access the application that is created for remote control of the system.

The interfaces for different measurements have the same structure, in this way students can remake one experiment in case of misunderstanding it at class. The design of some interface is shown in figure 2. All the interfaces are developed in LabVIEW which is a programming language accessible for students so they can change the application to make it easier to understand or even more complex.

The interface structure is easy to use because the information is organized in clusters. First, the student is informed about the identification data of the wireless system,

such as MAC and IP address. It has to be mentioned that each WiTAG system has its own MAC address that can not be changed. Next, he/she can see the number of iteration that are made and the path where the measured date is saved. The possibility of saving all the measured data or even only some of them could be really useful for subsequence reports or analysis. The output values are displayed on a graphical indicator (Waveform graph) or another type of indicator specific for each measurement (tubular, grid).

a. Temperature measurement

b. Current measurement

c. Analog Channel measurement Figure 2 Measurement interfaces The same hardware and software, with some small

modifications was developed also for monitoring and control of a laboratory oven used in material science for heating different type of metal and also a real industrial application. In this way students from Transilvania University of Brasov had the opportunity to work with an industrial – educational system.

IV. EDUCATIONAL AND INDUSTRIAL OF WITAG SYSTEM

At the same time, when the WiTAG system was used for teaching, the team of CVTC from Transilvania University of Brasov started also a research project having the aim in monitoring and control of an oven remotly. For this, were add some external components to the WiTAG system so that the two equipments could communicate and make the measurements properly.

So, because the limits of temperature was very high, between 0 – 1000 Celsius degrees, for a more accurate measurement was used an external temperature sensor, a K type thermocouple, connected to the analog connection of the WiTAG. This type of sensors is used in general in applications of industrial process control where the temperature is higher than 100 Celsius degrees. Also for increasing the autonomy of the new system was used a powerful battery then the standard one, a 3.3 V.

User interface for monitoring and control of temperature have at the beginning, like in general, information’s about the identification data of the wireless system, such as MAC and IP address. After that it can set the time in which to carry out measurements and can choose which type of thermocouple to be used from a list populated with all types of thermocouples.

For these input values, there are also output values representing by the current value of the measured temperature, which is displayed in a numeric and also a graphical indicator.

Control interface has a plus regarding the working parameters of the oven. The user can set the oven so that the tuning parameters to be completed in one of three (possible operating modes: P (Proportional), PI (Proportional Integral) and PID (Proportional Integral Derivative). This tree operating models represent the most frequent ways of operating for any heating equipment.

a. Monitoring Interface

b. Controling Interface

Figure 3 Monitoring and Control Interface of an Electrical

Oven (source Oros, R. G., Samoila, C. – “Conceperea și construirea unor senzori wireless cu aplicații la comanda echipamentelor și proceselor de încălzire “

(Designing and building of wireless sensors with applications used for control heating equipment and processes) 15 Oct. 201)

The prove that the WiTAG system can work properly in industrial environment staies the application that was

developed for a Romanian company that needed to implement some new technology on their galvanisation technological flow so they may pass the new conditions regarding environmental european commision check.

For this, the ideea was to realized a small hardware system that can monitor the temperature of a number of galvanic bath (at the end eight baths), and that can send this data to a server that is placed in another room. For this the WiTAG sistem was perfect, so a system that is used in industry now is also a laboratory equipment for students.

It was developed a user friendly interface in which is visible not only the evolution of the hole system also a graphical evolution of each bath, as shown in Figure4.

a. General Interface

b. Bath 3 Interface - Warping

Figure 4 Interfaces for Monitoring the Temparature for Eight

Galvanic Baths

(source Oros, R. G., Samoila, C. – “Conceperea și construirea unor senzori wireless cu aplicații la comanda echipamentelor și proceselor de încălzire “

Designing and building of wireless sensors with applications used for control heating equipment and processes) 15 Oct. 201)

V. CONCLUSIONS

For students it is very useful to be acquainted with all new technologies that the universities have the possibility to offer in their laboratories, even if are real laboratories, simulated laboratories, or virtual laboratories.

The trend of students being attracted to the new technologies is a well know fact and that has been very visible during latest years. This thing makes the remote controlled equipments to be one of the most preferred activities by students.

Automatic temperature control unit is the main aspect of electric oven through which correlates the power absorbed by the elements necessary technological heaters temperature regime, leading to a reduction in specific consumption of electricity by the electro thermal receiver and process technology.

In this way students are going to be better prepared for the challenges that real world offers.

REFERENCES

[1] Doru Ursutiu, Cornel Samoila, Petru Cotfas, Marius Moga, “Wireless Technologies in Medical Field”, Int. Conf. on Mobile Learning IMCL 2007, Amman, Jordan, 2007

[2] Marius Ghercioiu, Silviu Folea, and Jani Monoses, “The IP Sensor - a WiFi Sensor TAG”, ICOMP-07, Las Vegas, Nevada, USA June 25-28, 2007

[3] Oros, R. G., Samoilă, C. - Cercetări privind comanda cu senzori wireless din clasa WiTAG a temperaturii din cuptoarele industriale, Sesiunea de Comunicări Ştiinţifice a Şcolii Doctorale „Creativitate şi Inventică”, Mai 2009

[4] Oros, R. G., Jinga, V., Samoila, C., Ursutiu, D - New Technologies – WITAG for temperature and presure monitoring in critical areas of chemical equipments, Republica Cehă, Mai 2010

[5] Oros, R. G., Samoila, C. – “Conceperea și construirea unor senzori wireless cu aplicații la comanda echipamentelor și proceselor de încălzire “ (Designing and building of wireless sensors with applications used for control heating equipment and processes) 15 Oct. 2011

[6] Ursutiu D., Samoila C., Cotfas P., “Creativity in Remote Laboratory and Virtual Instrumentation”, Int. Conference on Technology, Communication and Education, Kuwait, 7-8 April.,2008

[7] http://www.tag4m.com/