Campbell Siemens TC35T GSM User manual

Siemens TC35T GSM
Digital Transceiver
Instructions for Use
With Campbell Scientific
Dataloggers
Issued 11.12.03
Copyright 2003 Campbell Scientific Ltd.

Guarantee
This equipment is guaranteed against defects in materials and
workmanship. This guarantee applies for twelve months from date of
delivery. We will repair or replace products which prove to be defective
during the guarantee period provided they are returned to us prepaid. The
guarantee will not apply to:
•Equipment which has been modified or altered in any way without the
written permission of Campbell Scientific
•Batteries
•Any product which has been subjected to misuse, neglect, acts of God
or damage in transit.
Campbell Scientific will return guaranteed equipment by surface carrier
prepaid. Campbell Scientific will not reimburse the claimant for costs
incurred in removing and/or reinstalling equipment. This guarantee and the
Company’s obligation thereunder is in lieu of all other guarantees,
expressed or implied, including those of suitability and fitness for a
particular purpose. Campbell Scientific is not liable for consequential
damage.
Please inform us before returning equipment and obtain a Repair
Reference Number whether the repair is under guarantee or not. Please
state the faults as clearly as possible, and if the product is out of the
guarantee period it should be accompanied by a purchase order.
Quotations for repairs can be given on request.
When returning equipment, the Repair Reference Number must be clearly
marked on the outside of the package.
Note that goods sent air freight are subject to Customs clearance fees
which Campbell Scientific will charge to customers. In many cases, these
charges are greater than the cost of the repair.
Campbell Scientific Ltd,
Campbell Park, 80 Hathern Road,
Shepshed, Loughborough, LE12 9GX, UK
Tel: [phone]
Fax: [phone]
Email: [email protected]
www.campbellsci.co.uk

i
Contents
1. Introduction.......................................................................1
1.1 Using GSM Networks for Data Transfer........................................................... 1
1.2 Network Coverage ............................................................................................ 2
1.3 Call Charges...................................................................................................... 3
2. Initial TC35T Setup ...........................................................3
3. Connection to a Datalogger .............................................4
3.1 SC932C Interface.............................................................................................. 4
3.2 SC932 Interface ................................................................................................ 5
3.3 SC32A Interface................................................................................................ 5
4. Power Supply....................................................................6
5. Antenna – General Notes ................................................. 6
5.1 Antenna Supplied by Campbell Scientific......................................................... 7
6. Configuring the TC35T for use with a Datalogger.......... 9
6.1 Setup ................................................................................................................. 9
6.2 Configuration for the GSM Network .............................................................. 10
6.3 Base Station .................................................................................................... 10
6.3.1 Configuring a Desk-Top Modem as a Base Station .............................. 11
6.3.2 Configuring the TC35T as a Base Station using PC208W.................... 11
6.3.3 Extending the Default Time-Outs.......................................................... 11
6.4 Ending a Call................................................................................................... 12
7. Datalogger Programming Hints ..................................... 14
7.1 Controlling the Power Consumption of the TC35T ........................................ 14
7.1.1 CR10X Program Example .................................................................. 14
7.2 Preventing TC35T Connection Problems ....................................................... 16
8. Fault Finding ................................................................... 16
8.1 General............................................................................................................ 16
8.2 The Base Station Fails to Get a Response from the Datalogger...................... 17
8.3 I get Errors when using the TC35T with Storage Modules............................. 18
Appendix A. Using the TC35T with the PIN Security
Feature Enabled........................................... A-1
A.1 Introduction...................................................................................................... 1
A.2 CR10X Program Example................................................................................ 1
Appendix B. Using the TC35T with the CR23X or CR5000
Dataloggers ................................................ B-1
B.1 Connections...................................................................................................... 1

ii
Appendix C. Details of Useful Configuration commands
for the TC35T ............................................C-1
C.1 Signal Quality Checks .......................................................................................1
C.2 Network Registration Checks ...........................................................................2
C.3 PIN configuration .............................................................................................4
Appendix D. Using the TC35T with Storage Modules .... D-1
D.1 Introduction.......................................................................................................1
D.2 The Problem Explained.....................................................................................1
D.3 Solutions ...........................................................................................................1
Figures
1. Connection of SC932C to TC35T .......................................................................4
2. Connecting the TC35T to a Datalogger ...............................................................5
3. Connection of SC32A to TC35T .........................................................................5
4. Antenna Supplied by Campbell Scientific ...........................................................8
Tables
1. TC35T Power Supply Connections......................................................................6

1
Use of the Siemens TC35T GSM Digital
Transceiver with Campbell Scientific
Dataloggers
This manual provides the technical information needed to use the Siemens TC35T module
with Campbell Scientific dataloggers. More comprehensive technical details of the unit can
be found in the Siemens TC35T hardware and software manuals. These manuals are not
supplied by Campbell Scientific with each TC35T as standard, but are available for
download (in Adobe Acrobat format) from Siemens Web Site (www.siemens.com/wm).
.
1. Introduction
The Siemens TC35T is a module designed to allow transfer of data across a GSM
(Global System for Mobile communications) digital cellular phone network. The
TC35T is a GSM digital transceiver; it can be thought of as a GSM ‘phone’
module without a handset, but which has an extra interface to allow data devices to
be connected. It has the following features:
•Standard RS232 serial port
•Relatively low power consumption
•Wide operating temperature range (-20°C to +55°C)
•Can be used to collect data from a datalogger at a similar speed to a land-
based 9600 baud modem in good reception areas
•Closely emulates a standard ‘Hayes style’ telephone modem; suitable for
situations where the datalogger instigates a call back to a base station, e.g. for
alarm purposes
The dimensions of the TC35T module are 65x74x33mm.
1.1 Using GSM Networks for Data Transfer
GSM networks are based on international standards and are widespread throughout
the world – see the web site www.gsm.org. Theoretically a GSM phone can be
used anywhere in the world if it is within range of a GSM network of the same
standard. For voice communications this theory almost works in practice, except
that many airtime providers (the company you pay for use of the phone) limit the
RS232 Serial Port
Male FME Antenna connector
Power connector

Siemens TC35T GSM Digital Transceiver
2
geographical range of most phones, and some do not have agreements with distant
providers.
For data transmission, most networks support the SMS (Short Message System),
which is not very practical for collecting large volumes of data, but can be useful
for sending alarm messages – see Technical Note 33 for more details of using
SMS. Larger networks support connections where an open data connection is
formed through the network. If this is supported, you may choose to connect to a
GSM data-phone either via a landline modem (landline to GSM) or by using a
second GSM phone in your office (GSM to GSM).
Before considering the use of the TC35T in your application, check with your
local GSM network company that they support the use of the Siemens TC35T for
the ‘non-transparent’ mode of data transmission, at 9600 baud. Check also that
they provide suitable routes to allow you to communicate with it, such as access
via land-line modems.
The current design of the TC35T will operate on GSM900 (900 MHz) or
GSM1800 (1800 MHz) networks. Whenever possible a GSM900 network should
be used as 1800 MHz networks (which includes the Orange and One to One
networks in the UK) are designed with smaller cells, and so phones (including the
TC35T) transmit at lower power outputs. All GSM1800 phones therefore have a
shorter range, which can cause more problems in areas of dubious signal coverage.
1.2 Network Coverage
One of the main advantages of using a cellphone network is being able to set up a
communications link to a datalogger virtually anywhere without installing land or
telephone lines. However, this only applies if your installation site is covered by a
suitable GSM network.
Within the UK the coverage of GSM networks is now better than the older analogue
networks. However, coverage in remote areas can still be quite poor and is not likely
to improve, as it offers little commercial advantage to the network companies.
Unless coverage is known to be good at the proposed site, we strongly recommended
that you actually test the coverage using a standard GSM handset (on the same
network as the TC35T is to be used) to measure the exact signal strength.
Even areas shown as having good coverage on network maps can have
‘holes’ due to local interference or other technical reasons, and so site
testing is recommended.
In areas of normal signal strength the TC35T can be used with a small, low cost
antenna. However, if the signal strength is marginal it may be possible to improve
reception using a raised and/or a higher gain antenna. Poor quality reception will
normally lead to breaks in communication or result in the PC software having to
make multiple requests to ensure uncorrupted data is collected. This will not
usually lead to data loss or corruption, but may result in longer calls and thus
higher call charges.
The network maintainer will be able to offer advice on coverage problems.
Campbell Scientific can also offer further advice on suitable antennae to suit the
application.
NOTE

Using with Campbell Scientific Dataloggers
3
1.3 Call Charges
Call charges on cellular-based phones are usually much higher than landline based
systems and can therefore be quite high for a long-term data collection campaign.
Careful choice of the tariffs available can result in a considerable reduction in the
total bill. Obviously the tariff chosen should allow use of the phone for data
transmission. Some very low cost packages are limited to voice only, but some
companies offer cheap data-only tariffs as well. Limiting calls to off-peak and
weekend periods can also result in major cost savings.
One major factor which can determine call costs is the method used to connect to
the remote TC35T. If you call the TC35T from a landline phone modem, you will
normally pay your landline phone company the same (high) cost as calling a voice
cellphone. This is independent of your agreement with the cellphone airtime
provider. In many cases it may be cheaper to buy an extra TC35T for your base
station, thus avoiding the use of the land-based phone line altogether. This could
also enable you to benefit from the special tariffs for data-only transmission
provided by the airtime companies. Also, the set-up time from TC35T to TC35T is
usually much lower and the overall call will thus be shorter and cheaper.
If you cannot use a base station TC35T, cheaper calls may also be possible by
programming the datalogger to call back to the land-line phone base station, as the
special airtime rates will normally apply to such calls too.
Where many calls have to be made in quick succession ISDN digital landlines can
be used with a digital terminal adaptor in the calling PC. If correctly supported and
set-up for the phone account by the network operator, the connection time can be
reduced to one or two seconds. This is done by setting the system to communicate
in a digital fashion throughout (UDI mode). Please contact Campbell Scientific
Ltd for further advice on this matter.
2. Initial TC35T Setup
Before the TC35T can be used or tested, it must be fitted with a ‘SIM’ (Subscriber
Identification Module) which enables it for use on a specific cellular telephone
network in a particular frequency band. For some networks, e.g. BT Cellnet in the
U.K, you need to specify the mode of data transfer. If this is required, request it to
work in ‘non-transparent mode’ at 9600 baud. This is the default setting for most
networks. Your airtime provider will normally supply you with an extra phone
number for the SIM specifically for data use.
The TC35T does not support the older transparent mode of
communication.
If possible, ensure that the SIM is configured so that it does not require a Personal
Identification Number (PIN) security code to be entered after the module is
powered up. The PIN can most easily be disabled by inserting it into a separate,
hand-held standard GSM phone and following the instructions contained in the
phone manual. If a separate phone is not available, please contact Campbell
Scientific for details of how to disable the PIN code for use with the TC35T. If this
is not possible, or if your airtime provider only allows operation with a PIN
enabled, please refer to Appendix A.
NOTE

Siemens TC35T GSM Digital Transceiver
4
Many SIM suppliers send the SIM with the PIN enabled and set to a
default PIN number. Check the documentation that came with your SIM.
3. Connection to a Datalogger
To enable normal operation of all Campbell Scientific peripherals which might
share the 9-way serial I/O port on the datalogger (e.g. Storage Modules), it is
necessary to use an interface between the datalogger and the TC35T. A number of
different interfaces can be used. Figure 2 shows a diagram of the recommended
interface and connections between a datalogger and the TC35T.
If using a CR23X or CR5000 datalogger, a simpler alternative connection is
possible using the RS232 port, if this is available. Please refer to Appendix B for
further details.
If you want to use the TC35T to communicate with storage modules
connected to the datalogger, please see Appendix D for advice on
possible problems you might encounter.
3.1 SC932C Interface
This is the preferred interface because:
•If the TC35T is programmed to respond to the DTR line state (see
‘Configuration for the GSM Network’, in Section 6, below), it allows the
datalogger to force the TC35T into an off-line state, if required.
•The SC932C only consumes <0.5mA when there is no communications and 10-
12mA when communications are active, from the datalogger 5V output. (This
is in addition to the power consumed by the TC35T which is approximately
20mA quiescent and 100-200 mA online.)
Connection to the TC35T is as follows:
25-Way D
Pin No.
9-Way D
Pin No.
23
3
75
20 4
SC932C TC35T Module
2
Figure 1 Connection of SC932C to TC35T
A commercial 9-25 way modem cable can be used in place of the
cable design shown in Figure 1. However, such a cable will have
extra connections that will increase the quiescent current drain of the
SC932(C) by 1 mA.
NOTE
NOTE
NOTE
Female Male