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General product description M20
Version 8 dated 15.03.00
15
Siemens Information and Communication Products
3.5
System requirements
The M20 is designed for use in a system environment comprising a GSM900 mobile radio network with one or more net-
work operators per country. A corresponding infrastructure for a configuration level suitable for the use of terminal de-
vices with 2 watts transmitting power is a basic requirement.
The functional environment for the M20 is constituted by a so-called base unit which supports the interfaces of the M20
(see
Fig. 3-2 M20 interface diagram
). The base unit must support at least 6 V power supply, a SIM card interface and an AT
command interface via the serial interface (V.24) or Man Machine Interface (MMI). The base unit can be, for example, a
GSM telephone, a ticket machine, some kind of vending machine, a hand-held device or another terminal device which
uses the GSM as a medium for transmitting voice, fax/data or short messages (SMS). The precondition is that the base
unit has to support the interfaces for the M20 operation as laid down in this technical description.
Fig. 3-2
M20 interface diagram
3.6
CE conformity
The M20 bears the CE symbol of conformity. This symbol guarantees the compliance of the design and implementation
of the M20 with the currently valid versions of the following EC directives.
• 89/336/EC (EMC Directive)
• 73/23/EC (Low Voltage Directive)
• 91/263/EC (Telecommunications Terminals Directive)
Standards:
• EMC:
ETS 300 342-1
• Safety:
EN 60950
• GSM network:
TBR 19, TBR 20
Serial Interface (RS232 / V24)
M20
SIM-Reader
Buzzer
Hook-switch
Dot-Display
2lines 16char
Keypad
4x6 Matrix
Antenna
Handset
6V
Power supply
SIM
Digital Audio Interface /
Voiceband Serial Interface
Power supply indicator
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*Man Machine In