Sentek PLUS, Руководство по оборудованию, Страница: 13 / 58

System Setup
Introduction
Copyright © 2005-2012 Sentek Pty Ltd All rights reserved Page 5
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Preparation, assembly and installation should generally be completed in the order of the steps in this
section. Efficiencies might be gained by experienced installers altering the order of the steps taken.
For example; although the sensor normalisation and configuration process is described below in the
section Probe Configuration, it is recommended that the probe be normalised, configured and tested prior
to field installation. This will help ensure that all hardware and data transfer aspects of the system are
working before installation begins.
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O O S S T T I I N N G G
A Sentek PLUS probe must have access to the internet and somewhere to send its data to. It needs
a SIM card that will allow the modem to connect to the internet and a computer that is set up as an FTP
server which can be accessed via the internet. The probe will make a connection to the internet at each
upload interval, log in to the FTP server and copy the data files to the computer directory specified.
Note: The internet access and FTP server should be set up prior to assembling and
installing the hardware.
Buying a SIM card and data packet plan for modem
Each Sentek PLUS system will require a SIM card for the modem. This SIM card must have a data plan
associated with it and must have reasonable coverage in the area where the probe will be installed. This
data plan is similar to what is needed for accessing the internet on your mobile (cell) phone.
It is not necessary to get a plan with cheaper voice calls, SMS rates, voice mail options or other such
features, as the probe will only use the data features of the plan, thus the GPRS or NextG data part of the
plan must be the cheapest aspect.
For use of the Dial-in feature, the SIM card must have a data (CSD) number that can be called.
When sourcing the SIM card and data plan make certain of the factors detailed below:
No Session Fees
Every time data is uploaded to the internet from the probe the network provider may charge what is
called a session fee or flag fall. For systems uploading frequently this can become very expensive
.
A typical session fee is around 25 cents. If uploads occur every 3 hours (8 uploads/day) this would cost
around $60 per month, on top of data usage charges. Therefore, it is advised that a plan with no session
fess be used.
Low Data Rates
To keep costs down, It is important when choosing a plan that you try to assess how much data you will be
uploading, and how often you will be uploading it before choosing a plan accordingly.
Most data plans work in much the same way as a voice plan, costing a certain amount each month for a
certain volume of data, and once this has been exceeded a charge for the excess data is applied.
Example plan:
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Base cost of $5 per month
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No session fees
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2,000 KB included per month
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1 cent per excess KB
If 1,800 KB is used, this plan will cost $5 per month, if however 2,200 KB
is used in a month that month’s
usage will come to $7.
A probe logging every 15 minutes and uploading every 90 minutes will use roughly 1,000
– 1,500 KB each
month.