TECHNICAL REFERENCE AND USER’S GUIDE
REV A
GSM GATEWAY
GT20 AND GT10 MOTHERBOARD
The GT20 motherboard is a card that contains on it two GSM modules, two SIM card
ports, two extension units, power processing unit, interfaces for connections, two exter-
nal antenna inputs, processor that controls functions of all those units and auxiliary cir-
cuits. See the figure below for circuit locations.
S1: SIM slot for GSM module 1,
G1: GSM module 1,
A1: Analog extension for GSM module 1,
S2: SIM slot for GSM module 2,
G2: GSM module 2,
A2: Analog extension for GSM module 2,
C: Computer interface (reserved for
future use),
L: LED card,
P: Power circuitry,
The GT10 motherboard is a card that contains on it one GSM module, one SIM card
port, one extension unit, power processing unit, interfaces for connections, one external
antenna input, processor that controls functions of all those units and auxiliary circuits.
See the figure below for circuit locations.
S1: SIM slot for GSM module 1,
G1: GSM module 1,
A1: Analog extension for GSM module 1,
C: Computer interface (reserved for
future use),
L: LED card,
P: Power circuitry,
Besides, there is a LED group which can be seen from outside even when the plastic
cabinet is closed and which gives information about the operation of the module to the
users. Order of the 5 LEDs that are on the motherboard and their functions have been
given in the foolowing section:
4
Figure-3
Figure-4
POWER SUPPLY
The GT20/GT10 power supply - PS03 -, is an external power supply that has been
designed to operate on 230 VAC /50 Hz. mains supply. This adaptor turns the mains
supply into 48 VDC and transfers to GT20/GT10 via the corresponding connector.
GT20/GT10 turns the 48 VDC it has received from the adaptor to + 5 VDC, -48 VDC and 67
Vrms ring signal by the power-processing unit it includes.
Appearance of the PS03 power adaptor is seen in the figure below:
Dimensions of PS03 are 11 cm. x 6 cm. x 8 cm. and it weighs 0.2 kg.
3
Figure-2
