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tic system bus, while section 4 describes the solution
adopted for our lab that enables remotely controlling
two specific devices (a halogen lamp and a power
socket). The paper ends with some considerations
about the work already done and future directions.
2 REQUIREMENTS
Each weblab requires a specific place to accommo-
date the apparatus, the measurement equipment and
the servers. Usually, those places have characteristic
light incidence, temperature and humidity condi-
tions, containing all the equipment power supplied.
The necessity to adopt a weblab to support the prac-
tical work, 24 hours per day, 7 days per week, has
consequences in the power consumption and in the
results obtained from the experiments. Then, spe-
cific attention should be paid to the physical envi-
ronment where an experiment is running, namely
with light and temperature conditions. Besides the
possibility of controlling the artificial light, it may
also be required to change the natural light incidence
by controlling the blinds of the physical space where
a specific experiment is running. In some cases tem-
perature control may also be required, because: 1)
some experiments use specific materials that change
with temperature conditions, and 2) some measure-
ment equipment may require a specific temperature
to work properly. This will lead to better results and
to avoid the damage of the equipment. An additional
requirement that should be considered is the ability
to switch off each device of the weblab, when not in
use. If possible of being done remotely, the all lab
may be switched off when a specific experiment
ends. Latter, when another experiment is starting,
the remote user may turn it on. This will contribute
to a reduction of the power consumption and hence
of the energy costs. Additionally, it may also be de-
sirable to reinitialize a certain device by applying an
off/on sequence. These suggestions/requirements
depend on whether the device and apparatus to be
switched off/on requires a setup procedure or not.
For example, it will not be reasonable to switch off
an Instrumentation Server used in a weblab by just
pulling out the plug from the power socket, because
it may damage the software installed on it. In this
case, it will be required to control remotely an UPS
(Uninterrupted Power Supply) to make a soft reset
or to turn the Instrumentation Server off. If all these
setup and reinitialization considerations are sup-
ported through remote control, then the technical
support, usually made by a technician, may be re-
duced or even suppressed, which also contributes to
reduce the weblab maintenance costs. Moreover,
switching off all devices and the apparatus, when not
in use, reduces the ageing effects, which also con-
tributes to the quality of the results obtained from
the remote experiments.
To address all the previous points, we propose using
a specific architecture with a standard domotic sys-
tem bus, usually implemented in smart houses. The
advantage of using a standard solution is that all
institutions currently supporting weblabs may
quickly adopt it with small development efforts.
3 PROPOSED ARCHITECTURE
Commonly, weblabs are idealized for specific ex-
periments. Although several weblab architectures
have been described in related literature, to the best
of our knowledge, few have considered the ability to
remotely control the physical space as well as the
power sockets where the lab devices connect to. At
this point two situations are common: 1) this re-
quirement is not even considered; 2) in-house spe-
cific solutions are used to tackle the problem. To
address both situations we propose weblab designers
to considerate the use of a standard domotic system
bus, in the way illustrated in figure 1. This proposed
architecture contains two servers: the Instrumenta-
tion Server and the Web Server, both connected
through an Intranet. All devices available in the we-
blab, namely the experiment apparatus, Webcams,
and the measurement equipment are controlled by
the Instrumentation Server that will sends/receives
basic signals to control and monitor each device. At
the same time, the Instrumentation Server transfers
information to/from the Web Server enabling the
interface between remote users and the lab. Another
relevant aspect presented in the proposed architec-
ture is the UPS. This unit is connected to the Instru-
mentation Server via a serial RS232 connection, and
to a power socket controlled by the domotic system
bus. By turning off this power socket, the UPS will
send a signal to the Instrumentation Server, instruct-
ing him to initiate a software shut down sequence.
This avoids the application under execution in the
Instrumentation Server, from being damaged be-
cause of a sudden power failure (i.e. an off com-
mand) or an improper shut down sequence. Users
must establish a Web connection to the Web Server
so they can download the Web interfaces designed
for a specific device (PC, PDA, Smart Phone or Mo-
bile phone), to control the weblab. The Web Server
should also contain the relevant pedagogical con-
tents, supported by a database together with a Vir-
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